EP4666503A1 - Time division multiplexing (tdm) for 8-port sounding reference signals (srs) - Google Patents

Time division multiplexing (tdm) for 8-port sounding reference signals (srs)

Info

Publication number
EP4666503A1
EP4666503A1 EP24706094.0A EP24706094A EP4666503A1 EP 4666503 A1 EP4666503 A1 EP 4666503A1 EP 24706094 A EP24706094 A EP 24706094A EP 4666503 A1 EP4666503 A1 EP 4666503A1
Authority
EP
European Patent Office
Prior art keywords
srs
ports
symbols
tdm
network node
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP24706094.0A
Other languages
German (de)
French (fr)
Inventor
Sven JACOBSSON
Siva Muruganathan
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Telefonaktiebolaget LM Ericsson AB
Original Assignee
Telefonaktiebolaget LM Ericsson AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
Publication of EP4666503A1 publication Critical patent/EP4666503A1/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0048—Allocation of pilot signals, i.e. of signals known to the receiver
    • H04L5/0051—Allocation of pilot signals, i.e. of signals known to the receiver of dedicated pilots, i.e. pilots destined for a single user or terminal
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2602—Signal structure
    • H04L27/261—Details of reference signals
    • H04L27/2613—Structure of the reference signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2602—Signal structure
    • H04L27/261—Details of reference signals
    • H04L27/2613—Structure of the reference signals
    • H04L27/26132—Structure of the reference signals using repetition
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/0001—Arrangements for dividing the transmission path
    • H04L5/0003—Two-dimensional division
    • H04L5/0005—Time-frequency
    • H04L5/0007—Time-frequency the frequencies being orthogonal, e.g. OFDM(A) or DMT
    • H04L5/0012—Hopping in multicarrier systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/0001—Arrangements for dividing the transmission path
    • H04L5/0014—Three-dimensional division
    • H04L5/0023—Time-frequency-space
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/0091—Signalling for the administration of the divided path, e.g. signalling of configuration information
    • H04L5/0094—Indication of how sub-channels of the path are allocated

Definitions

  • TDM TIME DIVISION MULTIPLEXING
  • SRS sounding reference signals
  • 3GPP Third Generation Partnership Project
  • 4G also referred to as Long Term Evolution (LTE)
  • 5G also referred to as New Radio (NR)
  • Such systems provide, among other features, broadband communication between network nodes, such as base stations, and mobile wireless devices (WD), as well as communication between network nodes and between WDs.
  • the 3GPP is also developing standards for Sixth Generation (6G) wireless communication networks.
  • Numerology In the time domain, NR downlink (DL) and uplink (UL) transmissions are organized into equally sized subframes of 1 ms each. A subframe is further divided into multiple slots of equal duration. The slot length depends on the numerology (i.e., on the subcarrier spacing (SCS) and the cyclic prefix (CP)). For 15 kHz SCS, there is only one slot per subframe. In general, for 15 ⁇ 2 ⁇ kHz SCS, where ⁇ ⁇ ⁇ 0,1,2,3,4 ⁇ is the SCS configuration, there are 2 ⁇ slots per subframe. Each slot consists of 14 symbols (unless extended CP is configured for which each slot consists of 12 symbols).
  • SCS subcarrier spacing
  • CP cyclic prefix
  • a system bandwidth is divided into RBs each corresponding to 12 contiguous subcarriers.
  • One subcarrier during one symbol interval forms one RE, which is the smallest physical resource in NR.
  • SRS Sounding reference signal
  • the usage of SRS includes, e.g., deriving the appropriate transmission/reception beams and/or to perform link adaptation (i.e., setting the transmission rank and the modulation and coding scheme (MCS)), and for determining physical downlink shared channel (PDSCH) and physical uplink shared channel (PUSCH) precoding matrices.
  • MCS modulation and coding scheme
  • the SRS is configured via radio resource control (RRC) signaling, where parts of the configuration may be updated (for reduced latency) via medium access control (MAC) control element (CE) signaling.
  • RRC configuration includes, for example, the SRS resource allocation (the physical mapping and the sequence to use) as well as the time- domain behavior (aperiodic, semi-persistent, or periodic).
  • DCI downlink control information
  • PDCCH physical downlink control channel
  • SRS-Config :: SEQUENCE ⁇ srs-ResourceSetToReleaseList SEQUENCE (SIZE(1..maxNrofSRS- ResourceSets)) OF SRS-ResourceSetId OPTIONAL, -- Need N srs-ResourceSetToAddModList SEQUENCE (SIZE(1..maxNrofSRS- ResourceSets)) OF SRS-ResourceSet OPTIONAL, -- Need N srs-ResourceToReleaseList SEQUENCE (SIZE(1..maxNrofSRS- Resources)) OF SRS-ResourceId OPTIONAL, -- Need N srs-ResourceToAddModList SEQUENCE (SIZE(1..maxNrofSRS- Resources)) OF SRS-ResourceId OPTIONAL, -- Need N srs-ResourceToAddModList SEQUENCE (SIZE(1..maxNrofSRS- Resources)) OF SRS-ResourceId OPTIONAL, -- Need N sr
  • ⁇ resources will be transmitted as part of an SRS resource set, where each SRS resource set contains one or more SRS resources.
  • NR supports configuration of up to 16 SRS resource sets and 64 SRS resources per bandwidth part (BWP). Furthermore, NR supports be periodic, semi-persistent, or aperiodic SRS transmissions: ⁇ Periodic SRS (p-SRS): SRS resource sets and SRS resources are RRC configured.
  • An SRS resource configuration includes slot periodicity and offset, which determines SRS transmission occasions;
  • sp-SRS Semi-persistent SRS
  • An SRS resource configuration includes slot periodicity and offset, and SRS transmissions are activated/deactivated using MAC CE signaling; and ⁇ Aperiodic SRS (ap-SRS): SRS resource sets and SRS resources are RRC configured.
  • An SRS resource-set configuration includes slot offset, and SRS transmissions are dynamically triggered via 2-bit “SRS request” field in DCI (e.g., in DCI Format 0_1 or DCI Format 1_1). All SRS resources in an SRS resource set must share the same time-domain behavior.
  • the SRS resource-set configuration determines, e.g., SRS usage, power control (PC) parameters, and slot offset for ap-SRS.
  • PC power control
  • the SRS resource configuration determines, e.g., the SRS time-and-frequency allocation, the SRS sequence, the periodicity and offset for p-SRS/sp-SRS.
  • SRS resource set configuration An SRS resource set is configured with the following in RRC (see ASN code in 3GPP TS 38.331 version 17.2.0):
  • SRS-ResourceSet :: SEQUENCE ⁇ srs-ResourceSetId SRS-ResourceSetId, srs-ResourceIdList SEQUENCE (SIZE(1..maxNrofSRS- ResourcesPerSet)) OF SRS-ResourceId OPTIONAL, -- Cond Setup resourceType CHOICE ⁇ aperiodic SEQUENCE ⁇ aperiodicSRS-ResourceTrigger INTEGER (1..maxNrofSRS- TriggerStates-1), csi-RS NZP-CSI-RS-ResourceId OPTIONAL, -- Cond NonCodebook slotOffset INTEGER
  • the slot offset is configured by the higher-layer parameter slotOffset and sets the delay from the PDCCH trigger reception to the start of the SRS transmission.
  • the resource usage which is configured by the higher-layer parameter usage sets constraints and assumptions on the resource properties (see 3GPP TS 38.214 for further details).
  • SRS resource sets may be configured with one of four different usages: antennaSwitching, codebook, nonCodebook, or beamManagement.
  • An SRS resource set that is configured with usage antennaSwitching is used for reciprocity-based DL precoding (i.e., used to sound the channel in the UL so that the network node may use reciprocity to set a suitable DL precoders).
  • the WD is expected to transmit one SRS port per WD antenna port.
  • An SRS resource set that is configured with usage codebook is used for CB-based UL transmission (i.e., used to sound the different WD antennas and help the network node to determine/signal a suitable UL precoder, transmission rank, and MCS for PUSCH transmission).
  • An SRS resource set that is configured with usage nonCodebook is used for non- codebook (NCB)-based UL transmission.
  • NCB non- codebook
  • the WD transmits one SRS resource per candidate beam (suitable candidate beams are determined by the WD based on CSI-reference signal (RS) measurements in the DL and, hence, reciprocity needs to hold).
  • the network node may then, by indicating a subset of these SRS resources, determine which UL beam(s) that the WD should apply for PUSCH transmission.
  • One UL layer will be transmitted per indicated SRS resource.
  • An SRS resource set that is configured with usage beamManagement is used (mainly for frequency bands above 6 GHz (i.e., for FR2)) to evaluate different WD analog beams (e.g., panels).
  • the WD transmits one SRS resource per analog beam, and the network node will perform a reference signal received power (RSRP) measurement per transmitted SRS resource and, in this way, determine a suitable WD beam that is reported to the WD.
  • RSRP reference signal received power
  • the associated channel state information reference signal (CSI-RS) (this configuration is only applicable for NCB-based UL transmission) for each of the possible resource types.
  • CSI-RS channel state information reference signal
  • the associated CSI-RS resource is determined by the higher-layer parameter csi-RS.
  • p-SRS/sp-SRS the associated CSI-RS resource is determined by the higher- layer parameter associatedCSI-RS.
  • the PC parameters e.g., alpha and p0 are used for setting the SRS transmission power.
  • SRS has its own UL PC scheme in NR (see 3GPP TS 38.213 for further details), which specifies how the WD should split the available output power between two or more SRS ports during one SRS transmit occasion (an SRS transmit occasion is a time window within a slot where SRS transmission is performed).
  • SRS-Resource SEQUENCE ⁇ srs-ResourceId SRS-ResourceId, nrofSRS-Ports ENUMERATED ⁇ port1, ports2, ports4 ⁇ , ptrs-PortIndex ENUMERATED ⁇ n0, n1 ⁇ OPTIONAL, -- Need R transmissionComb CHOICE ⁇ n2 SEQUENCE ⁇ combOffset-n2 INTEGER (0..1), cyclicShift-n2 INTEGER (0..7) ⁇ , n4 SEQUENCE ⁇ combOffset-n4 INTEGER (0..3), cyclicShift-n4 INTEGER (0..11) ⁇ resourceMapping SEQUENCE ⁇ startPosition INTEGER (0..5), nrofSymbols ENUMERATED ⁇ n1, n2, n4 ⁇
  • CSs allow multiplexing of SRS ports on a same comb offset, but there is a limit on how many CSs that may be used per comb offset (8 for comb 2 and 12 for comb 4); o
  • the time-domain position within a given slot, configured with the higher- layer parameter resourceMapping which includes: ⁇ The time-domain start position, which is limited to be one of the last 6 symbols, configured by the higher-layer parameter startPosition; ⁇ The number of symbols for the SRS resource (that may be set to 1, 2 or 4), configured by the higher-layer parameter nrofSymbols; and ⁇ The repetition factor (that may be set to 1, 2 or 4) configured by the higher-layer parameter repetitionFactor.
  • the sounding bandwidth, frequency-domain position and shift, and frequency- hopping pattern of an SRS resource (i.e., which part of the transmission bandwidth that is occupied by the SRS resource) is set through the higher-layer parameters freqDomainPosition, freqDomainShift, and the freqHopping parameters c-SRS, b-SRS, and b-hop.
  • freqDomainPosition i.e., which part of the transmission bandwidth that is occupied by the SRS resource
  • freqHopping parameters c-SRS, b-SRS, and b-hop The smallest possible sounding bandwidth is 4 RBs.
  • the higher-layer parameter resourceType determines whether the SRS resource is transmitted as periodic, aperiodic (singe transmission triggered by DCI), or semi persistent (same as periodic except for the start and stop of the periodic transmission is controlled through MAC-CE signaling instead of RRC signaling).
  • the higher-layer parameter sequenceId specifies how the SRS sequence is initialized.
  • the higher-layer parameter spatialRelationInfo configures the spatial relation for the SRS beam with respect to another RS (which could be another SRS, a synchronization signal block (SSB) or a CSI-RS). If an SRS resource has a spatial relation to another SRS resource, then this SRS resource should be transmitted with the same beam (i.e., virtualization) as the indicated SRS resource.
  • transmission comb 8 is supported for which the number of CSs per comb offset is 6 (see higher-layer parameter transmissionComb-n8-r17).
  • an SRS resource may occupy any of the 14 symbols in a slot but the number of symbols per SRS resource is limited to 4 (see higher-layer parameter resourceMapping-r16).
  • an SRS the number of symbols per SRS resource is up to 14 (see higher-layer parameter resourceMapping-r17).
  • FIG.1 An illustration of how an SRS resource could be allocated in time and frequency within a slot (note that semi-persistent/periodic SRS resources typically span several slots), is provided in FIG.1 for NR 3GPP Rel-15/Rel-16.
  • SRS antenna switching It is desirable for the network node to sound all WD antennas (where sounding an antenna implies that SRS is transmitted from that antenna) but costly to equip the WD with many transmit (Tx) chains. Therefore, SRS antenna switching was introduced in NR 3GPP Rel-15 for WDs equipped with more receive (Rx) chains than Tx chains. If a WD support antenna switching, it will report so by means of WD-capability signaling (see, e.g., Table 1, copied from 3GPP TS 38.306).
  • Table 1 SRS antenna-switching capabilities supported by the WD. supportedSRS-TxPortSwitch supportedSRS-TxPortSwitch-v1610 t1r2 t1r1-t1r2 t1r4 t1r1-t1r2-t1r4 t2r4 t1r1-t1r2-t2r2-t2r4 t2r2 t1r1-t2r2 t4r4 t1r1-t2r2-t4r4 t1r4-t2r4 t1r1-t2r2-t4r4 t1r4-t2r4 t1r1-t1r2-t2r2-t1r4-t2r4 t2r4 t1r1-t1r2-t2r2-t1r4-t2r4 t2r4 t1r1-t1r2-t2r2-t1r4-t2r4
  • the left column in Table 1 lists
  • a WD reports t1r2 it means that it has two receive (Rx) antennas (i.e., it has two Rx chains) but only has the possibility of transmitting from one of those antennas at a time (i.e., it has one Tx chain).
  • Rx receive
  • Tx chains transmit ports
  • two single-port SRS resources may be configured for the WD such that it may sound both Rx ports using a Tx transmit port with an antenna switch in between.
  • additional WD capabilities for SRS antenna-switching were introduced, which are shown in the right column of Table 1.
  • the WD may indicate support for sounding only a subset of Rx antennas, which may save WD power consumption and SRS overhead at the cost of reduced channel knowledge at the network node.
  • the WD capability t1r1-t1r2 indicates that the network node may configure one single-port SRS resource (no antenna switching) or two single-port SRS resources (same as for the capability t1r2 described above) per SRS resource set with usage antennaSwitching.
  • antenna switching was extended to up to 6 or 8 Rx ports, and 1, 2, or 4 Tx chains.
  • the WD may indicate support for antenna-switching configurations beyond 4 Rx via higher-layer parameter srs-AntennaSwitchingBeyond4RX-r17 (see 3GPP TS 38.306 for further details).
  • SRS coverage Schemes to improve the coverage of SRS have been adopted in NR, including repetition of an SRS resource and/or frequency hopping.
  • FIG.2 for reference, is an example of SRS transmission without frequency hopping and/or repetition.
  • the entire SRS bandwidth is sounded in a single symbol.
  • An example of SRS frequency hopping is provided in FIG.3.
  • SRS bandwidth different parts are sounded in each of four different OFDM symbols, which means that the power spectral density (PSD) for SRS will improve (by four times compared to the baseline case in FIG.2), at the cost of more symbols being used for SRS and a shorter SRS sequence length per OFDM symbol.
  • PSD power spectral density
  • An example of SRS repetition is provided in FIG.4.
  • one SRS resource is repeated in four consecutive OFDM symbols, which means that the PSD for SRS will improve (by four times compared to the baseline case in FIG.2), at the cost of more symbols being used for SRS and decreased SRS (multiplexing) capacity.
  • FIG.5 shows a p-SRS resource (with periodicity one) over two adjacent UL slots.
  • the frequency-hopping configuration is the same as in FIG.3, the repetition factor is 2, and the number of SRS symbols per slot is 4. Note that in this example (and in all the previous examples) all hops (highlighted in blue in the figure(s)) belong to the same SRS resource.
  • SRS capacity Schemes to improve SRS capacity have been adopted in NR, which include using transmission comb 2, 4 or 8 (i.e., sounding only every 2 nd , 4 th , or 8 th subcarrier within the configured bandwidth), and multiplexing several SRS ports onto the same transmission comb by using different CSs.
  • FIG.6 illustrates how 2 or 4 single-port SRS resources may be multiplexed onto the same configured SRS bandwidth by using transmission comb 2 and 4, respectively.
  • the different SRS resources have been configured with different comb offsets (i.e., RRC-configured with different values of the parameter combOffset).
  • 2 and 4 single-port SRS resources are multiplexed using transmission comb 2 and 4, respectively.
  • the SRS base sequences which are used in NR, are such that they are pairwise orthogonal under CSs. Utilizing this property, it is possible to multiplex several SRS ports onto the same transmission comb by using different CSs (and the same base sequence) for different SRS ports.
  • the maximum number of CSs is 8, 12, and 6 for transmission comb 2, 4, and 8, respectively.
  • the different SRS ports belonging to the same SRS resource will be configured with a port-specific CS per SRS port.
  • FIG.7 is a discrete-time domain representation (after computing an inverse discrete Fourier transform (IDFT)), the (absolute value of the) correlation between a cyclically shifted base sequence and the corresponding non-shifted base sequence.
  • IDFT inverse discrete Fourier transform
  • the transmission comb is 2 (such that the maximum number of CSs is 8) and the sequence length is 48 (which corresponds to an SRS transmission spanning 8 resource blocks (RBs)).
  • the sequences are orthogonal and, hence, may be separated by means of simple signal processing (e.g., through time-domain windowing).
  • the sequence length is 48 samples, and the maximum number of CSs is 8 (transmission comb is 2).
  • transmission comb is 2.
  • FIGS.8 and 9 are examples of how the (absolute value of the) correlation in FIG.7 is affected when the SRS is transmitted over a frequency-selective channel, i.e., a channel with a non-zero delay spread (in FIGS. 8 and 9, the delay spread is 15 discrete samples long).
  • the orthogonality between the SRS sequences is lost due to the frequency-selective channel.
  • increasing the number of (used) CS results in more interference (compare the upper and lower part of the figure).
  • the maximum channel delay spread for which there is no interference is inversely proportional to the product of the subcarrier spacing, the transmission comb, and number of (occupied, and uniformly separated) CSs.
  • the sequence length is 48 samples, and the maximum number of CSs is 8 (transmission comb is 2).
  • 4 equidistant SRS ports i.e., CSs
  • 8 equidistant SRS ports are multiplexed on a same comb offset.
  • the maximum number of ports per SRS resource will be increased from 4 (in legacy NR) to 8 for SRS resources in an SRS resource set with usage ‘codebook’ or ‘antennaSwitching’.
  • all 8 ports of said resources may be mapped to onto each of ⁇ symbols, where ⁇ ⁇ ⁇ 1, 2, 4, 8, 10, 12, 14 ⁇ .
  • TDM TDM will be supported for 8-port SRS resources.
  • Agreement for single SRS resource in an SRS resource set with usage ‘codebook’ for 8Tx PUSCH or ‘antennaSwitching’ (i.e., for 8T8R antenna switching) when the SRS resource is configured with 8 ports and m OFDM symbols (m > 1), support the case of 8 ports mapped onto the m OFDM symbols
  • Option 1 Different SRS ports are mapped onto different OFDM symbols (i.e., TDM)
  • FFS m may be legacy values, i.e., 2,4,[8,10,12,14].
  • Some embodiments advantageously provide methods, network nodes and wireless devices for time division multiplexing (TDM) for eight port sounding reference signals (SRS). Some embodiments may provide configuration, signaling, restrictions and rules for SRS TDM, including formulas for mapping SRS ports to cyclic shifts and comb offsets.
  • mapping may be such that number of SRS ports and symbols is the same for each subset): ⁇ The subsets of SRS ports are non-overlapping. The number of SRS ports over all subsets may be equal to the configured number of SRS ports; and/or ⁇ The subsets of SRS symbols are non-overlapping. The number of symbols over all subsets may be smaller than or equal to the configured number of SRS symbols.
  • the SRS ports may be mapped to SRS symbols according to: ⁇ Sequential mapping pattern; and/or ⁇ Cyclical mapping pattern.
  • the SRS ports within each subset are mapped to comb offset and cyclic shifts according to a mapping rule such that: ⁇ The same set of comb offsets and cyclic shifts are used for all subsets; or ⁇ The set of comb offsets and cyclic shifts over all subsets are the same as the set of comb offsets and cyclic shifts for an SRS resource not configured with TDM.
  • Some embodiments provide configurations of TDM for SRS, which may improve SRS coverage for SRS resources spanning different numbers of symbols.
  • Some embodiments provide a configuration of TDM together with legacy SRS coverage- enhancement schemes (i.e., repetition, frequency hopping, resource block level partial frequency sounding (RPFS)).
  • a method in a network node configured to communicate with a wireless device, WD includes configuring the WD with cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped.
  • the method also includes configuring the WD to perform SRS transmissions according to the cyclical mapping.
  • a number of SRS ports in a subset of SRS ports of the N subsets is a ratio, ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ⁇ ⁇ ⁇ ⁇ ⁇ denotes a number of SRS ports per SRS resource and ⁇ ⁇ is a TDM factor equal to N.
  • ⁇ ⁇ is equal to 2 when TDM is configured and ⁇ ⁇ is equal to 1, otherwise.
  • ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ ⁇ , being an integer are configured, where ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ is equal to M and is radio resource control, RRC, configured .
  • RRC radio resource control
  • the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , being greater than 1 is allowed only when an SRS resource is configured with one or more of repetition, frequency hopping and RPFS.
  • the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ is not an integer, then the nearest integer less than the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ is a number of SRS symbols per subset of SRS ports. In some embodiments, when the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , is not an integer, then a number of symbols per subset of SRS ports varies over the N subsets of SRS ports.
  • a number of symbols and a number of SRS ports per subset of SRS ports varies over the N subset of ports.
  • a ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ is greater than 1 and repetition, frequency hopping and RPFS are not configured, then ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ SRS ports per subset of SRS symbols are repeated over ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , OFDM symbols.
  • the method includes configuring the WD to transmit a repetition of ⁇ ⁇ ⁇ ⁇ ⁇ SRS ports in each of a plurality of successive sets of ⁇ ⁇ symbols. In some embodiments, the method includes configuring the WD to sound SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured. In some embodiments, a same set of comb offsets and cyclic shifts, CS, are occupied by each subset of SRS ports. In some embodiments, a comb offset for an antenna port is based at least in part on the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ .
  • a cyclic shift for an antenna port is based at least in part on the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ .
  • a hopping pattern for each subset of an number ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ of SRS ports is a same hopping pattern for a ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ port SRS resource.
  • the method includes receiving from the network node cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped.
  • the method also includes cyclically mapping the N subsets of SRS ports to the M OFDM symbols.
  • the method further includes performing SRS transmissions according to the cyclical mapping.
  • a number of SRS ports in a subset of SRS ports of the N subsets is a ratio, ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ⁇ ⁇ ⁇ ⁇ ⁇ denotes a number of SRS ports per SRS resource and ⁇ ⁇ is a TDM factor equal to N.
  • the method includes transmitting a repetition of ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ SRS ports in each of a plurality of successive sets of ⁇ ⁇ symbols.
  • the method includes sounding SRS ports in a subset of SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured.
  • time division multiplexing and frequency hopping are both configured, using a same frequency counter to determine a frequency domain position for all subsets of SRS ports.
  • a network node configured to communicate with a wireless device, WD, is provided.
  • the network node is configured to configure the WD with cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped.
  • the network node is also configured to configure the WD to perform SRS transmissions according to the cyclical mapping.
  • a number of SRS ports in a subset of SRS ports of the N subsets is a ratio, ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ⁇ ⁇ ⁇ ⁇ ⁇ denotes a number of SRS ports per SRS resource and ⁇ ⁇ is a TDM factor equal to N.
  • ⁇ ⁇ is equal to 2 when TDM is configured and ⁇ ⁇ is equal to 1, otherwise.
  • ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ ⁇ , being an integer are configured, where ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ is equal to M and is radio resource control, RRC, configured.
  • RRC radio resource control
  • the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , being greater than 1 is allowed only when an SRS resource is configured with one or more of repetition, frequency hopping and RPFS.
  • the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ is not an integer, then the nearest integer less than the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ is a number of symbols per subset of SRS ports. In some embodiments, when the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , is not an integer, then a number of symbols per subset of SRS ports varies over the N subsets of SRS ports.
  • a number of symbols and a number of SRS ports per subset of SRS ports varies over the N subset of ports.
  • a ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ is greater than 1 and repetition, frequency hopping and RPFS are not configured, then ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ SRS ports per subset of SRS symbols are repeated over ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , OFDM symbols.
  • the network node is configured to configure the WD to transmit a repetition of ⁇ ⁇ ⁇ ⁇ ⁇ SRS ports in each of a plurality of successive sets of ⁇ ⁇ symbols.
  • the network node is configured to configure the WD to sound SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured.
  • a same set of comb offsets and cyclic shifts, CS are occupied by each subset of SRS ports.
  • a comb offset for an antenna port is based at least in part on the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ .
  • a cyclic shift for an antenna port is based at least in part on the ratio, ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ .
  • a hopping pattern for each subset of an number P of SRS ports is a same hopping pattern for a P port SRS resource.
  • a WD configured to communicate with a network node, is provided.
  • the WD is configured to receive from the network node cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped.
  • the WD is configured to cyclically map the N subsets of SRS ports to the M OFDM symbols.
  • the WD is also configured to perform SRS transmissions according to the cyclical mapping.
  • a number of SRS ports in a subset of SRS ports of the N subsets is based on a ratio, ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ⁇ ⁇ ⁇ ⁇ ⁇ denotes a number of SRS ports per SRS resource and ⁇ ⁇ is a TDM factor equal to N.
  • the WD is configured to transmit a repetition of ⁇ ⁇ ⁇ ⁇ ⁇ SRS ports in each of a plurality of successive sets of ⁇ ⁇ symbols.
  • the WD is configured to sound SRS ports in a subset of SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured.
  • time division multiplexing and frequency hopping are both configured, using a same frequency counter to determine a frequency domain position for all subsets of SRS ports.
  • FIG.1 is an example of SRS resource allocation
  • FIG.2 illustrates SRS transmission without frequency hopping or repetition
  • FIG.3 illustrates SRS transmission with frequency hopping
  • FIG.4 illustrates SRS transmission with repetition
  • FIG.5 illustrates SRS transmission over two adjacent UL slots
  • FIG.6 illustrates 2 and 4 multiplexed single port SRS resources
  • FIG.7 illustrates correlation between cyclically shifted SRS base sequences with corresponding unshifted base sequence (for sequence length of 48 samples and a maximum of cyclic shift of 8)
  • FIG.8 illustrates correlation between cyclically shifted SRS base sequences which have been transmitted over a frequency-selective channel, with the corresponding non- shifted base sequence, for 4 equidistant SRS ports
  • FIG.9 illustrates correlation between cyclically shifted SRS base sequences
  • relational terms such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements.
  • the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein.
  • the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
  • the joining term, “in communication with” and the like may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example.
  • electrical or data communication which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example.
  • the term “coupled,” “connected,” and the like, may be used herein to indicate a connection, although not necessarily directly, and may include wired and/or wireless connections.
  • the term “network node” used herein may be any kind of network node comprised in a radio network which may further comprise any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multi- standard radio (MSR) radio node such as MSR BS, multi-cell/multicast coordination entity (MCE), integrated access and backhaul (IAB) node, relay node, donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node,
  • the network node may also comprise test equipment.
  • radio node used herein may be used to also denote a wireless device (WD) such as a wireless device (WD) or a radio network node.
  • WD wireless device
  • UE user equipment
  • the WD herein may be any type of wireless device capable of communicating with a network node or another WD over radio signals, such as wireless device (WD).
  • the WD may also be a radio communication device, target device, device to device (D2D) WD, machine type WD or WD capable of machine to machine communication (M2M), low-cost and/or low-complexity WD, a sensor equipped with WD, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (IoT) device, or a Narrowband IoT (NB-IOT) device, etc.
  • the generic term “radio network node” is used.
  • Radio network node may comprise any of base station, radio base station, base transceiver station, base station controller, network controller, RNC, evolved Node B (eNB), Node B, gNB, Multi-cell/multicast Coordination Entity (MCE), IAB node, relay node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH).
  • RNC evolved Node B
  • MCE Multi-cell/multicast Coordination Entity
  • IAB node Multi-cell/multicast Coordination Entity
  • RRU Remote Radio Unit
  • RRH Remote Radio Head
  • WCDMA Wide Band Code Division Multiple Access
  • WiMax Worldwide Interoperability for Microwave Access
  • UMB Ultra Mobile Broadband
  • GSM Global System for Mobile Communications
  • functions described herein as being performed by a wireless device or a network node may be distributed over a plurality of wireless devices and/or network nodes.
  • the functions of the network node and wireless device described herein are not limited to performance by a single physical device and, in fact, may be distributed among several physical devices.
  • all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.
  • FIG.10 a schematic diagram of a communication system 10, according to an embodiment, such as a 3GPP-type cellular network that may support standards such as LTE and/or NR (5G), which comprises an access network 12, such as a radio access network, and a core network 14.
  • a 3GPP-type cellular network that may support standards such as LTE and/or NR (5G)
  • 5G NR
  • the access network 12 comprises a plurality of network nodes 16a, 16b, 16c (referred to collectively as network nodes 16), such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 18a, 18b, 18c (referred to collectively as coverage areas 18).
  • Each network node 16a, 16b, 16c is connectable to the core network 14 over a wired or wireless connection 20.
  • a first wireless device (WD) 22a located in coverage area 18a is configured to wirelessly connect to, or be paged by, the corresponding network node 16a.
  • a second WD 22b in coverage area 18b is wirelessly connectable to the corresponding network node 16b.
  • a plurality of WDs 22a, 22b are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole WD is in the coverage area or where a sole WD is connecting to the corresponding network node 16.
  • the communication system may include many more WDs 22 and network nodes 16.
  • a WD 22 may be in simultaneous communication and/or configured to separately communicate with more than one network node 16 and more than one type of network node 16.
  • a WD 22 may have dual connectivity with a network node 16 that supports LTE and the same or a different network node 16 that supports NR.
  • WD 22 may be in communication with an eNB for LTE/E-UTRAN and a gNB for NR/NG-RAN.
  • the communication system 10 may itself be connected to a host computer 24, which may be embodied in the hardware and/or software of a standalone server, a cloud- implemented server, a distributed server or as processing resources in a server farm.
  • the host computer 24 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider.
  • the connections 26, 28 between the communication system 10 and the host computer 24 may extend directly from the core network 14 to the host computer 24 or may extend via an optional intermediate network 30.
  • the intermediate network 30 may be one of, or a combination of more than one of, a public, private or hosted network.
  • the intermediate network 30, if any, may be a backbone network or the Internet. In some embodiments, the intermediate network 30 may comprise two or more sub-networks (not shown).
  • the communication system of FIG.10 as a whole enables connectivity between one of the connected WDs 22a, 22b and the host computer 24.
  • the connectivity may be described as an over-the-top (OTT) connection.
  • the host computer 24 and the connected WDs 22a, 22b are configured to communicate data and/or signaling via the OTT connection, using the access network 12, the core network 14, any intermediate network 30 and possible further infrastructure (not shown) as intermediaries.
  • the OTT connection may be transparent in the sense that at least some of the participating communication devices through which the OTT connection passes are unaware of routing of uplink and downlink communications.
  • a network node 16 may not or need not be informed about the past routing of an incoming downlink communication with data originating from a host computer 24 to be forwarded (e.g., handed over) to a connected WD 22a. Similarly, the network node 16 need not be aware of the future routing of an outgoing uplink communication originating from the WD 22a towards the host computer 24.
  • a network node 16 is configured to include an SRS unit 32 which may be configured to associate a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols, the associating being according to one of a sequential mapping pattern and a cyclical mapping pattern.
  • the SRS unit 32 may be configured to configure the WD 22 with cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols.
  • a wireless device 22 is configured to include a determination unit 34 which may be configured to determine the subset of SRS symbols based on a received mapping configuration.
  • the determination unit 34 may be configured to cyclically map N subsets of SRS ports to M OFDM symbols Example implementations, in accordance with an embodiment, of the WD 22, network node 16 and host computer 24 discussed in the preceding paragraphs will now be described with reference to FIG.11.
  • a host computer 24 comprises hardware (HW) 38 including a communication interface 40 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system 10.
  • the host computer 24 further comprises processing circuitry 42, which may have storage and/or processing capabilities.
  • the processing circuitry 42 may include a processor 44 and memory 46.
  • the processing circuitry 42 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions.
  • the processor 44 may be configured to access (e.g., write to and/or read from) memory 46, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).
  • memory 46 may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).
  • Processing circuitry 42 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by host computer 24.
  • Processor 44 corresponds to one or more processors 44 for performing host computer 24 functions described herein.
  • the host computer 24 includes memory 46 that is configured to store data, programmatic software code and/or other information described herein.
  • the software 48 and/or the host application 50 may include instructions that, when executed by the processor 44 and/or processing circuitry 42, causes the processor 44 and/or processing circuitry 42 to perform the processes described herein with respect to host computer 24.
  • the instructions may be software associated with the host computer 24.
  • the software 48 may be executable by the processing circuitry 42.
  • the software 48 includes a host application 50.
  • the host application 50 may be operable to provide a service to a remote user, such as a WD 22 connecting via an OTT connection 52 terminating at the WD 22 and the host computer 24.
  • the host application 50 may provide user data which is transmitted using the OTT connection 52.
  • the “user data” may be data and information described herein as implementing the described functionality.
  • the host computer 24 may be configured for providing control and functionality to a service provider and may be operated by the service provider or on behalf of the service provider.
  • the processing circuitry 42 of the host computer 24 may enable the host computer 24 to observe, monitor, control, transmit to and/or receive from the network node 16 and or the wireless device 22.
  • the communication system 10 further includes a network node 16 provided in a communication system 10 and including hardware 58 enabling it to communicate with the host computer 24 and with the WD 22.
  • the hardware 58 may include a communication interface 60 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 10, as well as a radio interface 62 for setting up and maintaining at least a wireless connection 64 with a WD 22 located in a coverage area 18 served by the network node 16.
  • the radio interface 62 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers.
  • the communication interface 60 may be configured to facilitate a connection 66 to the host computer 24.
  • the connection 66 may be direct or it may pass through a core network 14 of the communication system 10 and/or through one or more intermediate networks 30 outside the communication system 10.
  • the hardware 58 of the network node 16 further includes processing circuitry 68.
  • the processing circuitry 68 may include a processor 70 and a memory 72.
  • the processing circuitry 68 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions.
  • FPGAs Field Programmable Gate Array
  • ASICs Application Specific Integrated Circuitry
  • the processor 70 may be configured to access (e.g., write to and/or read from) the memory 72, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).
  • the network node 16 further has software 74 stored internally in, for example, memory 72, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the network node 16 via an external connection.
  • the software 74 may be executable by the processing circuitry 68.
  • the processing circuitry 68 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by network node 16.
  • Processor 70 corresponds to one or more processors 70 for performing network node 16 functions described herein.
  • the memory 72 is configured to store data, programmatic software code and/or other information described herein.
  • the software 74 may include instructions that, when executed by the processor 70 and/or processing circuitry 68, causes the processor 70 and/or processing circuitry 68 to perform the processes described herein with respect to network node 16.
  • processing circuitry 68 of the network node 16 may include an SRS unit 32 which may be configured to associate a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols, the associating being according to one of a sequential mapping pattern and a cyclical mapping pattern.
  • the SRS unit 32 may be configured to configure the WD 22 with cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols.
  • the communication system 10 further includes the WD 22 already referred to.
  • the WD 22 may have hardware 80 that may include a radio interface 82 configured to set up and maintain a wireless connection 64 with a network node 16 serving a coverage area 18 in which the WD 22 is currently located.
  • the radio interface 82 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers.
  • the hardware 80 of the WD 22 further includes processing circuitry 84.
  • the processing circuitry 84 may include a processor 86 and memory 88.
  • the processing circuitry 84 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions.
  • the processor 86 may be configured to access (e.g., write to and/or read from) memory 88, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).
  • memory 88 may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).
  • the WD 22 may further comprise software 90, which is stored in, for example, memory 88 at the WD 22, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the WD 22.
  • the software 90 may be executable by the processing circuitry 84.
  • the client application 92 may be operable to provide a service to a human or non-human user via the WD 22, with the support of the host computer 24.
  • an executing host application 50 may communicate with the executing client application 92 via the OTT connection 52 terminating at the WD 22 and the host computer 24.
  • the client application 92 may receive request data from the host application 50 and provide user data in response to the request data.
  • the OTT connection 52 may transfer both the request data and the user data.
  • the client application 92 may interact with the user to generate the user data that it provides.
  • the processing circuitry 84 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by WD 22.
  • the processor 86 corresponds to one or more processors 86 for performing WD 22 functions described herein.
  • the WD 22 includes memory 88 that is configured to store data, programmatic software code and/or other information described herein.
  • the software 90 and/or the client application 92 may include instructions that, when executed by the processor 86 and/or processing circuitry 84, causes the processor 86 and/or processing circuitry 84 to perform the processes described herein with respect to WD 22.
  • the processing circuitry 84 of the wireless device 22 may include a determination unit 34 that determines the subset of SRS symbols based on a received mapping configuration.
  • the determination unit 34 may be configured to cyclically map N subsets of SRS ports to M OFDM symbols
  • the inner workings of the network node 16, WD 22, and host computer 24 may be as shown in FIG.11 and independently, the surrounding network topology may be that of FIG.10.
  • the OTT connection 52 has been drawn abstractly to illustrate the communication between the host computer 24 and the wireless device 22 via the network node 16, without explicit reference to any intermediary devices and the precise routing of messages via these devices.
  • Network infrastructure may determine the routing, which it may be configured to hide from the WD 22 or from the service provider operating the host computer 24, or both. While the OTT connection 52 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).
  • the wireless connection 64 between the WD 22 and the network node 16 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the WD 22 using the OTT connection 52, in which the wireless connection 64 may form the last segment.
  • a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve.
  • the measurement procedure and/or the network functionality for reconfiguring the OTT connection 52 may be implemented in the software 48 of the host computer 24 or in the software 90 of the WD 22, or both.
  • sensors may be deployed in or in association with communication devices through which the OTT connection 52 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 48, 90 may compute or estimate the monitored quantities.
  • the reconfiguring of the OTT connection 52 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect the network node 16, and it may be unknown or imperceptible to the network node 16. Some such procedures and functionalities may be known and practiced in the art.
  • measurements may involve proprietary WD signaling facilitating the host computer’s 24 measurements of throughput, propagation times, latency and the like.
  • the measurements may be implemented in that the software 48, 90 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 52 while it monitors propagation times, errors, etc.
  • the host computer 24 includes processing circuitry 42 configured to provide user data and a communication interface 40 that is configured to forward the user data to a cellular network for transmission to the WD 22.
  • the cellular network also includes the network node 16 with a radio interface 62.
  • the network node 16 is configured to, and/or the network node’s 16 processing circuitry 68 is configured to perform the functions and/or methods described herein for preparing/initiating/maintaining/ supporting/ending a transmission to the WD 22, and/or preparing/terminating/ maintaining/supporting/ending in receipt of a transmission from the WD 22.
  • the host computer 24 includes processing circuitry 42 and a communication interface 40 that is configured to a communication interface 40 configured to receive user data originating from a transmission from a WD 22 to a network node 16.
  • the WD 22 is configured to, and/or comprises a radio interface 82 and/or processing circuitry 84 configured to perform the functions and/or methods described herein for preparing/initiating/maintaining/ supporting/ending a transmission to the network node 16, and/or preparing/ terminating/maintaining/supporting/ending in receipt of a transmission from the network node 16.
  • FIGS.10 and 11 show various “units” such as SRS unit 32, and determination unit 34 as being within a respective processor, it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, the units may be implemented in hardware or in a combination of hardware and software within the processing circuitry.
  • FIG.12 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIGS.10 and 11, in accordance with one embodiment.
  • the communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIG.11.
  • the host computer 24 provides user data (Block S100).
  • the host computer 24 provides the user data by executing a host application, such as, for example, the host application 50 (Block S102).
  • the host computer 24 initiates a transmission carrying the user data to the WD 22 (Block S104).
  • the network node 16 transmits to the WD 22 the user data which was carried in the transmission that the host computer 24 initiated, in accordance with the teachings of the embodiments described throughout this disclosure (Block S106).
  • the WD 22 executes a client application, such as, for example, the client application 92, associated with the host application 50 executed by the host computer 24 (Block S108).
  • FIG.13 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG.10, in accordance with one embodiment.
  • the communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS.10 and 11.
  • the host computer 24 provides user data (Block S110).
  • the host computer 24 provides the user data by executing a host application, such as, for example, the host application 50.
  • the host computer 24 initiates a transmission carrying the user data to the WD 22 (Block S112).
  • the transmission may pass via the network node 16, in accordance with the teachings of the embodiments described throughout this disclosure.
  • the WD 22 receives the user data carried in the transmission (Block S114).
  • FIG.14 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG.10, in accordance with one embodiment.
  • the communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS.10 and 11.
  • the WD 22 receives input data provided by the host computer 24 (Block S116).
  • the WD 22 executes the client application 92, which provides the user data in reaction to the received input data provided by the host computer 24 (Block S118).
  • the WD 22 provides user data (Block S120).
  • the WD provides the user data by executing a client application, such as, for example, client application 92 (Block S122).
  • the executed client application 92 may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the WD 22 may initiate, in an optional third substep, transmission of the user data to the host computer 24 (Block S124). In a fourth step of the method, the host computer 24 receives the user data transmitted from the WD 22, in accordance with the teachings of the embodiments described throughout this disclosure (Block S126).
  • FIG.15 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG.10, in accordance with one embodiment.
  • the communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS.10 and 11.
  • the network node 16 receives user data from the WD 22 (Block S128). In an optional second step, the network node 16 initiates transmission of the received user data to the host computer 24 (Block S130). In a third step, the host computer 24 receives the user data carried in the transmission initiated by the network node 16 (Block S132).
  • FIG.16 is a flowchart of an example process in a network node 16 for time division multiplexing (TDM) for eight port sounding reference signals (SRS).
  • TDM time division multiplexing
  • SRS port sounding reference signals
  • One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 68 (including the SRS unit 32), processor 70, radio interface 62 and/or communication interface 60.
  • Network node 16 such as via processing circuitry 68 and/or processor 70 and/or radio interface 62 and/or communication interface 60 is configured to associate a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols, the associating being according to one of a sequential mapping pattern and a cyclical mapping pattern (Block S134).
  • SRS ports in the subset of SRS ports are mapped to comb offsets and cyclic shifts according to a mapping rule.
  • a same set of comb offsets and cyclic shifts are used for all subsets of a plurality of SRS port subsets. In some embodiments, a same set of comb offsets and cyclic shifts over all of subsets of the plurality of SRS port subsets are used for an SRS resource not configured with time division duplexing, TDM.
  • the one of the sequential mapping pattern and the cyclical mapping pattern is radio resource control, RRC, configured for each SRS resource of a plurality of SRS resources.
  • RRC radio resource control
  • FIG.17 is a flowchart of an example process in a WD 22 for time division multiplexing (TDM) for eight port sounding reference signals (SRS).
  • TDM time division multiplexing
  • SRS eight port sounding reference signals
  • WD 22 such as via processing circuitry 84 and/or processor 86 and/or radio interface 82 is configured to receive a configuration of a one of a sequential mapping pattern and a cyclical mapping pattern for associating a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols (Block S136).
  • the process also includes determining the subset of SRS symbols based on the received configuration (Block S138).
  • the configuration is received on radio resource control, RRC, signaling.
  • FIG.18 is a flowchart of an example process in a network node 16 for time division multiplexing (TDM) for eight port sounding reference signals (SRS).
  • TDM time division multiplexing
  • SRS eight port sounding reference signals
  • One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 68 (including the SRS unit 32), processor 70, radio interface 62 and/or communication interface 60.
  • Network node 16 such as via processing circuitry 68 and/or processor 70 and/or radio interface 62 and/or communication interface 60 is configured to configure the WD 22 with cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped (Block S140).
  • a number of SRS ports in a subset of SRS ports of the N subsets is a ratio, ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ⁇ ⁇ ⁇ ⁇ ⁇ denotes a number of SRS ports per SRS resource and ⁇ ⁇ is a TDM factor equal to N.
  • ⁇ ⁇ is equal to 2 when TDM is configured and ⁇ ⁇ is equal to 1, otherwise.
  • ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ ⁇ , being an integer are configured, where ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ is equal to M and is radio resource control, RRC, configured .
  • RRC radio resource control
  • the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , being greater than 1 is allowed only when an SRS resource is configured with one or more of repetition, frequency hopping and RPFS.
  • the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ is not an integer, then the nearest integer less than the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ is a number of SRS symbols per subset of SRS ports. In some embodiments, when the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , is not an integer, then a number of symbols per subset of SRS ports varies over the N subsets of SRS ports.
  • a number of symbols and a number of SRS ports per subset of SRS ports varies over the N subset of ports.
  • a ratio, ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ is greater than 1 and repetition, frequency hopping and RPFS are not configured, then ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ SRS ports per subset of SRS symbols are repeated over ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , OFDM symbols.
  • the method includes configuring the WD 22 to transmit a repetition of ⁇ ⁇ ⁇ ⁇ ⁇ SRS ports in each of a plurality of successive sets of ⁇ ⁇ symbols. In some embodiments, the method includes configuring the WD 22 to sound SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured. In some embodiments, a same set of comb offsets and cyclic shifts, CS, are occupied by each subset of SRS ports. In some embodiments, a comb offset for an antenna port is based at least in part on the ratio, ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ .
  • a cyclic shift for an antenna port is based at least in on the ratio, ⁇ ⁇ / ⁇ .
  • a hopping pattern for each subset of an number ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ of SRS ports is a same hopping pattern for a ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ port SRS resource.
  • FIG.19 is a flowchart of an example process in a WD 22 for time division multiplexing (TDM) for eight port sounding reference signals (SRS).
  • One or more blocks described herein may be performed by one or more elements of WD 22 such as by one or more of processing circuitry 84 (including the determination unit 34), processor 86 and/or radio interface 82.
  • WD 22 such as via processing circuitry 84 and/or processor 86 and/or radio interface 82 is configured to receive from the network node 16 cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped (Block S144).
  • the method also includes cyclically mapping the N subsets of SRS ports to the M OFDM symbols (Block S146).
  • the method further includes performing SRS transmissions according to the cyclical mapping (Block S148).
  • a number of SRS ports in a subset of SRS ports of the N subsets is a ratio, ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ , the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ⁇ ⁇ ⁇ ⁇ ⁇ denotes a number of SRS ports per SRS resource and ⁇ ⁇ is a TDM factor equal to N.
  • the method includes transmitting a repetition of ⁇ ⁇ ⁇ ⁇ ⁇ SRS ports in each of a plurality of successive sets of ⁇ ⁇ symbols.
  • the method includes sounding SRS ports in a subset of SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured.
  • time division multiplexing and frequency hopping are both configured, using a same frequency counter to determine a frequency domain position for all subsets of SRS ports.
  • TDM time division multiplexing
  • SRS eight port sounding reference signals
  • ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ denotes the (maximum) number of SRS ports per subset of SRS symbols is configured.
  • ⁇ ⁇ ⁇ ⁇ ⁇ is the number of SRS ports per SRS resource and ⁇ ⁇ is a “TDM factor” (note of “TDM factor”, a different terminology may be used in 3GPP specifications for this parameter).
  • the parameter ⁇ ⁇ will be used in later embodiments to derive the comb offset and CS allocation for an SRS resource configured with TDM.
  • ⁇ ⁇ ⁇ 2 if TDM is configured, e.g., via higher-layer p arameter timeDivisionDuplexing-r18 as per the following example in ASN, and ⁇ ⁇ 1 otherwise.
  • SRS-Resource :: SEQUENCE ⁇ srs-ResourceId SRS-ResourceId, nrofSRS-Ports ENUMERATED ⁇ port1, ports2, ports4, ports8 ⁇ , ... [[ ... timeDivisionDuplexing-r18 ENUMERATED ⁇ enabled ⁇ OPTIONAL, -- Cond 8Tx ...
  • the field timeDivisionDuplexing-r18 is present only if the number of SRS ports in the SRS resource is set to 8, e.g., as described in Table 2.
  • Table 2 Conditional presence of timeDivisionDuplexing-r18 field.
  • the field is optional present if higher-layer parameter 8Tx nrofSRS-Ports is set to ports8. Otherwise, it is absent.
  • ⁇ ⁇ may be explicitly configured (e.g., as per the following example in abstract syntax notation (ASN)) or may be implicitly derived based on other SRS configuration parameters (e.g., on the number of SRS symbols configured per SRS resource).
  • SRS-Resource :: SEQUENCE ⁇ srs-ResourceId SRS-ResourceId, nrofSRS-Ports ENUMERATED ⁇ port1, ports2, ports4, ports8 ⁇ , ... [[ ... timeDivisionDuplexing-r18 SEQUENCE ⁇ nrofSRS-PortsPerSymbol-r18 ENUMERATED ⁇ n1, n2, n4 ⁇ ⁇ OPTIONAL, -- Cond 8Tx ⁇ ...
  • the only allowed RRC configured combinations of ⁇ ⁇ ⁇ and ⁇ ⁇ are those resulting in ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ being an integer:
  • ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ ⁇ 1 is allowed only if SRS resource is configured with one or more of repetition, frequency hopping, or RPFS.
  • SRS ports 0, ... , ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 1 are transmitted in SRS symbols 0, ... , ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ ⁇ 1, SRS ports ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ , ... , 2 ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 1 are ⁇ , ... ,2 ⁇ ⁇ ⁇ / ⁇ ⁇ 1, etc.
  • FIG.20 shows an to the above embodiments (with sequential mapping) for the case when the number of SRS ports per subset of SRS symbols is ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 4 (i.e., ⁇ ⁇ ⁇ ⁇ ⁇ 8 and ⁇ ⁇ ⁇ 2), the number of SRS symbols is ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 8, the repetition factor is ⁇ ⁇ 4, and intra-slot frequency hopping is not configured.
  • FIG.20 shows SRS TDM combined with SRS repetition.
  • p0, p1, ..., p7 are the SRS ports.
  • the same frequency hopping counter is used to determine the frequency-domain position for all subsets of SRS ports.
  • all SRS ports within a subset of SRS ports may be sounded within a slot in which SRS is transmitted.
  • FIG.21 shows an example of SRS TDM according to the above embodiments for the case when the number of SRS ports per subset of SRS symbols is ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 4 (i.e., ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 8 and ⁇ ⁇ ⁇ 2), the number of SRS symbols is ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 8, the repetition factor is ⁇ ⁇ 2, and intra-slot frequency hopping over two hops is configured.
  • FIG.21 shows SRS TDM combined with SRS frequency hopping over two hops (per subset of ports).
  • p0, p1, ..., p7 are the SRS ports.
  • FIG.22 is an example of SRS TDM according to the above embodiments for the case when the number of SRS ports per subset of SRS symbols is ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 4 (i.e., ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 8 and ⁇ ⁇ ⁇ 2), the number of SRS symbols is ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 8, the repetition factor ⁇ 1, and intra-slot frequency hopping over four hops is configured.
  • SRS TDM is combined with SRS frequency hopping over four hops (per subset of ports).
  • p0, p1, ..., p7 are the SRS ports.
  • Cyclical mapping A benefit with the above approach (e.g., with the pattern in FIG.22) is that CSI may be acquired for each subset of SRS ports with a minimum time interval between the first and last transmission occasion of a same SRS port, which mitigates channel-aging effects.
  • the drawback with the above approach is that frequency hopping may cause phase discontinuities and, hence, the network node 16 may measure a phase shift between a first and second set of SRS ports without being able to determine whether this phase shift is due to the channel or due to the frequency hopping.
  • the orthogonal subsets of ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ SRS ports will be transmitted in a cyclic manner, e.g., as follows: S RS ports 0, ... , ⁇ ⁇ ⁇ ⁇ ⁇ 1 are transmitted in SRS symbols 0 , ⁇ , 2 ⁇ , 3 ⁇ , ... ⁇ , ... , 2 ⁇ ⁇ ⁇ ⁇ 1 are transmitted in SRS symbols 1 , ⁇ ⁇ 1, 2 ⁇ ⁇ 1, 3 ⁇ ⁇ 1, ... SRS ports 2 ⁇ ⁇ ⁇ ⁇ ⁇ , ... , 3 ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 1 are transmitted in SRS symbols 2 , ⁇ ⁇ 2, 2 ⁇ ⁇ 2, 3 ⁇ ⁇ 2, ... Etc.
  • the ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 1,2, ... , ⁇ ⁇ ⁇ orthogonal set of SRS ports: ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 1 ⁇ ⁇ ⁇ , ⁇ ⁇ ⁇ 1 ⁇ ⁇ ⁇ ⁇ 1, ... , ⁇ ⁇ ⁇ ⁇ ⁇ 1, are ⁇ ⁇ ⁇ 1 ⁇ , 1 ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 1 ⁇ , 2 ⁇ ⁇ ⁇ ⁇ ⁇ 1 ⁇ , 3 ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 1 ⁇ , ... .
  • all ⁇ ⁇ ⁇ ⁇ ⁇ SRS ports are transmitted in the first ⁇ ⁇ symbols, the 2 nd repetition of all ⁇ ⁇ ⁇ ⁇ ⁇ SRS ports are transmitted in the next ⁇ ⁇ symbols, etc.
  • the first TRP may just measure all ⁇ ⁇ ⁇ ⁇ ⁇ SRS ports in the first ⁇ ⁇ symbols with sufficient quality and does not need to measure the remaining repetitions.
  • FIG.23 shows an example of SRS TDM according to the above alternative embodiment for the case when the number of SRS ports per subset of SRS symbols is ⁇ ⁇ ⁇ ⁇ 4 (i.e., ⁇ ⁇ 8 and ⁇ ⁇ 2), the number of S ⁇ ⁇ ⁇ ⁇ ⁇ RS symbols is ⁇ ⁇ frequency hopping is not configured.
  • SRS TDM is combined with SRS repetition for an alternative embodiment.
  • p0, p1, ..., p7 are the SRS ports.
  • all SRS ports may be sounded before the frequency is hopped. This strategy is illustrated in FIG.24 for the same configuration as the pattern in FIG.21.
  • FIG.24 shows SRS TDM combined with SRS frequency hopping over two hops (per subset of ports) and with alternative mapping.
  • p0, p1, ..., p7 are the SRS ports.
  • the time-domain mapping pattern (i.e., sequential or cyclic mapping)
  • the time-domain mapping pattern may be RRC configured per SRS resource, for example as per the following (in ASN):
  • SRS-Resource :: SEQUENCE ⁇ srs-ResourceId SRS-ResourceId, nrofSRS-Ports ENUMERATED ⁇ port1, ports2, ports4, ports8 ⁇ , ... [[ ... timeDivisionDuplexing-r18 SEQUENCE ⁇ mappingPattern-r18 ENUMERATED ⁇ sequentialMapping, cyclicMapping ⁇ ⁇ OPTIONAL, -- Cond 8Tx ⁇ ...
  • subsets of SRS ports subsets of the occupied ⁇ ⁇ ⁇ ⁇ / ⁇ symbols. ⁇ ⁇ ⁇ ⁇
  • RRC configured values of ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ and ⁇ ⁇ are such that ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ / ⁇ ⁇ is not an integer, the number of symbols per subset of SRS ports may vary ports.
  • the number of symbols and the number of SRS ports per subset of SRS ports may vary over the subsets of SRS ports.
  • an SRS resource configured with TDM factor ⁇ ⁇ and ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ symbols will span a total ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ symbols.
  • the legacy (in existing NR specification) parameter ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ is reinterpreted as the number of OFDM symbols per subset of SRS ports.
  • the starting symbol position for the ⁇ th subset of SRS ports, ⁇ ⁇ 0,1, ... , ⁇ ⁇ ⁇ 1, is ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ , where ⁇ ⁇ is the RRC-configured starting position for the SRS resource.
  • the starting position may be explicitly configured, in RRC, for each subset of SRS ports.
  • the comb offset and cyclic shifts are configured using legacy RRC fields. Specifically, the higher- layer parameter transmissionComb for transmission comb 2 and 4, and transmissionComb-n8-r17 for transmission comb 8. To support this behavior, legacy SRS port-to-CS and SRS port-to-comb-offset formulas need to be modified, e.g., as per the following. In some embodiments, the same set of comb offsets and CSs are used for an 8-port SRS resource without regard to whether TDM is configured.
  • the set of comb offsets and CSs are different for different subsets of SRS ports.
  • the same set of comb offset and CSs are occupied by each subset of SRS ports, which simplifies co-scheduling of other SRS resources in a same set of time/frequency resources.
  • some example embodiments are considered, assuming that the first subset of SRS ports are 0, ... , ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 1, the second subset of SRS ports are ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ , ... , 2 ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 1, and so on.
  • SRS ports ⁇ ⁇ ⁇ ⁇ 1000, 1001, 1002, 1003 ⁇ are in a first subset and ⁇ ⁇ ⁇ ⁇ 1004, 1005, 1006, 1007 ⁇
  • the CS ⁇ ⁇ for antenna port ⁇ ⁇ is given by c s, ⁇ ⁇ ⁇ ⁇ 2 ⁇ ⁇ c s S , R m S a x .
  • ⁇ ⁇ is the maximum cs, ⁇ shifts per comb offset and ⁇ SRS given by: ⁇ SRS ⁇ ⁇ cs,max S ⁇ ⁇ mod ⁇ ⁇ ap ⁇ ⁇ 1000 ⁇ 2 ⁇ ⁇ ⁇ RS ⁇ ö
  • ⁇ S cs R S is the RRC-configured cyclic shift (contained in the higher-later parameter transmissionComb).
  • ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ 6 is equivalent to transmission comb 8 being configured. Note that if TDM is not configured, then ⁇ ⁇ ⁇ 1 according to a previous embodiment and the above formula reduces to a legacy port-to-CS formula.
  • the comb offset ⁇ ⁇ T C for antenna port ⁇ ⁇ is given by: S RS ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ TC ⁇ TC ⁇ ⁇ mod if ap ⁇ ⁇ SRS ⁇ 4, ⁇ mod ap ⁇ ⁇ 1000 ⁇ ⁇ 1001, 1003 ⁇ , and ⁇ cs,max ⁇ 6 ⁇ 2 ⁇ ⁇ SRS ⁇ ⁇ p arameter transmissionComb) and ⁇ , ... , ⁇ ⁇ 1 to a embodiment and the above formula reduces to a legacy port-to-comb-offset formula.
  • Cyclic-shift and/or comb-offset hopping will be supported for SRS in NR 3GPP Rel-18, which requires updated formulas for mapping SRS ports to comb offsets and cyclic shifts.
  • Hopping patterns and formulas for mapping SRS ports to comb offsets and cyclic shifts may be provided.
  • the hopping pattern and formulas, for each subset of ⁇ SRS ports may be the same as the hopping pattern for a ⁇ -port SRS resource.
  • Some embodiments may include one or more of the following: Embodiment A1.
  • a network node configured to communicate with a wireless device (WD), the network node configured to, and/or comprising a radio interface and/or comprising processing circuitry configured to: associate a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols, the associating being according to one of a sequential mapping pattern and a cyclical mapping pattern.
  • WD wireless device
  • processing circuitry configured to: associate a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols, the associating being according to one of a sequential mapping pattern and a cyclical mapping pattern.
  • Embodiment A2 The network node of Embodiment A1, wherein SRS ports in the subset of SRS ports are mapped to comb offsets and cyclic shifts according to a mapping rule.
  • Embodiment A2 wherein a same set of comb offsets and cyclic shifts are used for all subsets of a plurality of SRS port subsets.
  • Embodiment A4. The network node of Embodiment A3, wherein a same set of comb offsets and cyclic shifts over all of subsets of the plurality of SRS port subsets are used for an SRS resource not configured with time division duplexing, TDM.
  • Embodiment A5. The network node of any of Embodiments A1-A4, wherein the one of the sequential mapping pattern and the cyclical mapping pattern is radio resource control, RRC, configured for each SRS resource of a plurality of SRS resources.
  • RRC radio resource control
  • Embodiment A5 The network node of any of Embodiments A1-A5, wherein, when both time division multiplexing, TDM, and frequency hopping are configured, a plurality of SRS ports of the subset of SRS ports are sounded before frequency hopping.
  • Embodiment A7 The network node of Embodiment A6, wherein all SRS ports of the subset of SRS ports are sounded within a slot of SRS transmission.
  • Embodiment A8 The network node of any of Embodiments A1-A7, wherein, when both time division multiplexing, TDM, and frequency hopping are configured, a same frequency hopping counter is used to determine a frequency domain position for all subsets of SRS ports.
  • a method implemented in a network node comprising: associating a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols, the associating being according to one of a sequential mapping pattern and a cyclical mapping pattern.
  • Embodiment B2. The method of Embodiment B1, wherein SRS ports in the subset of SRS ports are mapped to comb offsets and cyclic shifts according to a mapping rule.
  • the method of Embodiment B2 wherein a same set of comb offsets and cyclic shifts are used for all subsets of a plurality of SRS port subsets.
  • Embodiment B3 wherein a same set of comb offsets and cyclic shifts over all of subsets of the plurality of SRS port subsets are used for an SRS resource not configured with time division duplexing, TDM.
  • Embodiment B5. The method of any of Embodiments B1-B4, wherein the one of the sequential mapping pattern and the cyclical mapping pattern is radio resource control, RRC, configured for each SRS resource of a plurality of SRS resources.
  • Embodiment B6 The method of any of Embodiments B1-B5, wherein, when both time division multiplexing, TDM, and frequency hopping are configured, a plurality of SRS ports of the subset of SRS ports are sounded before frequency hopping.
  • Embodiment B7 The method of Embodiment B6, wherein all SRS ports of the subset of SRS ports are sounded within a slot of SRS transmission.
  • Embodiment B8 The method of any of Embodiments B1-B7, wherein, when both time division multiplexing, TDM, and frequency hopping are configured, a same frequency hopping counter is used to determine a frequency domain position for all subsets of SRS ports.
  • a wireless device configured to communicate with an network node, the WD configured to, and/or comprising a radio interface and/or comprising processing circuitry configured to: receive a configuration of a one of a sequential mapping pattern and a cyclical mapping pattern for associating a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols; and determine the subset of SRS symbols based at least in part on the received mapping configuration.
  • Embodiment C2 The WD of Embodiment C1, wherein the configuration is received on radio resource control, RRC, signaling.
  • a method in a wireless device configured to communicate with an network node comprising: receiving a configuration of a one of a sequential mapping pattern and a cyclical mapping pattern for associating a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols; and determining the subset of SRS symbols based at least in part on the received mapping configuration.
  • Embodiment D2 The method of Embodiment D1, wherein the configuration is received on radio resource control, RRC, signaling.
  • RRC radio resource control
  • the concepts described herein may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or “module.” Any process, step, action and/or functionality described herein may be performed by, and/or associated to, a corresponding module, which may be implemented in software and/or firmware and/or hardware.
  • the disclosure may take the form of a computer program product on a tangible computer usable storage medium having computer program code embodied in the medium that may be executed by a computer. Any suitable tangible computer readable medium may be utilized including hard disks, CD-ROMs, electronic storage devices, optical storage devices, or magnetic storage devices.
  • These computer program instructions may also be stored in a computer readable memory or storage medium that may direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks.
  • the computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
  • the program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer.
  • the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
  • LAN local area network
  • WAN wide area network
  • Internet Service Provider for example, AT&T, MCI, Sprint, EarthLink, etc.
  • Abbreviations that may be used in the preceding description include: Abbreviation Explanation 3GPP Third Generation Partnership Project ap-SRS Aperiodic SRS ASN Abstract Syntax Notation BPSK Binary Phase Shift Keying BWP Bandwidth Part CA Carrier Aggregation CB Codebook CDM Code Division Multiplexing CE Control Element CP-OFDM Cyclic Prefix OFDM CRB Carrier RB CG Configured Grant CS Cyclic Shift CS-RNTI Configured Scheduling RNTI CSI Channel State Information DCI Downlink Control Information DFT Discrete Fourier Transform DFT-S-OFDM DFT Spread OFDM DG Dynamic Grant DL Downlink DMRS Demodulation RS FD-OCC Frequency Domain OCC FDD Frequency-Division Multiplexing FR1 Frequency Range 1 FR2 Frequency Range 2 IDFT Inverse DFT gNB gNodeB IE Information Element LSB Least Significant Bit LTE Long Term Evolution MAC

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

A method, network node and wireless device (WD) for time division multiplexing (TDM) for eight port sounding reference signals (SRS) are disclosed. According to one aspect, a method in a network node includes configuring the WD with cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped; and configuring the WD to perform SRS transmissions according to the cyclical mapping.

Description

TIME DIVISION MULTIPLEXING (TDM) FOR 8-PORT SOUNDING REFERENCE SIGNALS (SRS) TECHNICAL FIELD The present disclosure relates to wireless communications, and in particular, to time division multiplexing (TDM) for sounding reference signals (SRS) such as eight port SRS. BACKGROUND The Third Generation Partnership Project (3GPP) has developed and is developing standards for Fourth Generation (4G) (also referred to as Long Term Evolution (LTE)) and Fifth Generation (5G) (also referred to as New Radio (NR)) wireless communication systems. Such systems provide, among other features, broadband communication between network nodes, such as base stations, and mobile wireless devices (WD), as well as communication between network nodes and between WDs. The 3GPP is also developing standards for Sixth Generation (6G) wireless communication networks. Numerology In the time domain, NR downlink (DL) and uplink (UL) transmissions are organized into equally sized subframes of 1 ms each. A subframe is further divided into multiple slots of equal duration. The slot length depends on the numerology (i.e., on the subcarrier spacing (SCS) and the cyclic prefix (CP)). For 15 kHz SCS, there is only one slot per subframe. In general, for 15 ∙ 2ఓ kHz SCS, where ^^ ∈ ^0,1,2,3,4^ is the SCS configuration, there are 2ఓ slots per subframe. Each slot consists of 14 symbols (unless extended CP is configured for which each slot consists of 12 symbols). In the frequency domain, a system bandwidth is divided into RBs each corresponding to 12 contiguous subcarriers. One subcarrier during one symbol interval forms one RE, which is the smallest physical resource in NR. SRS In NR, a sounding reference signal (SRS) is used for providing channel state information (CSI) to the network node in the UL. The usage of SRS includes, e.g., deriving the appropriate transmission/reception beams and/or to perform link adaptation (i.e., setting the transmission rank and the modulation and coding scheme (MCS)), and for determining physical downlink shared channel (PDSCH) and physical uplink shared channel (PUSCH) precoding matrices. The SRS is configured via radio resource control (RRC) signaling, where parts of the configuration may be updated (for reduced latency) via medium access control (MAC) control element (CE) signaling. The RRC configuration includes, for example, the SRS resource allocation (the physical mapping and the sequence to use) as well as the time- domain behavior (aperiodic, semi-persistent, or periodic). For aperiodic SRS transmission, the RRC configuration does not activate an SRS transmission from the WD but instead a dynamic activation trigger is transmitted from the network node, via the downlink control information (DCI) in the physical downlink control channel (PDCCH), which instructs the WD to transmit the SRS once, at a predetermined time. SRS configuration When configuring SRS transmissions, the network node configures, through the SRS-Config IE, a list of SRS resources and a list of SRS resource sets (see below snippet of ASN from 3GPP Technical Standard (3GPP TS 38.331) version 17.2.0): SRS-Config ::= SEQUENCE { srs-ResourceSetToReleaseList SEQUENCE (SIZE(1..maxNrofSRS- ResourceSets)) OF SRS-ResourceSetId OPTIONAL, -- Need N srs-ResourceSetToAddModList SEQUENCE (SIZE(1..maxNrofSRS- ResourceSets)) OF SRS-ResourceSet OPTIONAL, -- Need N srs-ResourceToReleaseList SEQUENCE (SIZE(1..maxNrofSRS- Resources)) OF SRS-ResourceId OPTIONAL, -- Need N srs-ResourceToAddModList SEQUENCE (SIZE(1..maxNrofSRS- Resources)) OF SRS-Resource OPTIONAL, -- Need N ... } resources will be transmitted as part of an SRS resource set, where each SRS resource set contains one or more SRS resources. NR supports configuration of up to 16 SRS resource sets and 64 SRS resources per bandwidth part (BWP). Furthermore, NR supports be periodic, semi-persistent, or aperiodic SRS transmissions: ^ Periodic SRS (p-SRS): SRS resource sets and SRS resources are RRC configured. An SRS resource configuration includes slot periodicity and offset, which determines SRS transmission occasions; ^ Semi-persistent SRS (sp-SRS): SRS resource sets and SRS resources are RRC configured. An SRS resource configuration includes slot periodicity and offset, and SRS transmissions are activated/deactivated using MAC CE signaling; and ^ Aperiodic SRS (ap-SRS): SRS resource sets and SRS resources are RRC configured. An SRS resource-set configuration includes slot offset, and SRS transmissions are dynamically triggered via 2-bit “SRS request” field in DCI (e.g., in DCI Format 0_1 or DCI Format 1_1). All SRS resources in an SRS resource set must share the same time-domain behavior. In short, the SRS resource-set configuration determines, e.g., SRS usage, power control (PC) parameters, and slot offset for ap-SRS. The SRS resource configuration determines, e.g., the SRS time-and-frequency allocation, the SRS sequence, the periodicity and offset for p-SRS/sp-SRS. SRS resource set configuration An SRS resource set is configured with the following in RRC (see ASN code in 3GPP TS 38.331 version 17.2.0): SRS-ResourceSet ::= SEQUENCE { srs-ResourceSetId SRS-ResourceSetId, srs-ResourceIdList SEQUENCE (SIZE(1..maxNrofSRS- ResourcesPerSet)) OF SRS-ResourceId OPTIONAL, -- Cond Setup resourceType CHOICE { aperiodic SEQUENCE { aperiodicSRS-ResourceTrigger INTEGER (1..maxNrofSRS- TriggerStates-1), csi-RS NZP-CSI-RS-ResourceId OPTIONAL, -- Cond NonCodebook slotOffset INTEGER (1..32) OPTIONAL, -- Need S ..., [[ aperiodicSRS-ResourceTriggerList SEQUENCE (SIZE(1..maxNrofSRS-TriggerStates-2)) OF INTEGER (1..maxNrofSRS- TriggerStates-1) OPTIONAL -- Need M ]] }, semi-persistent SEQUENCE { associatedCSI-RS NZP-CSI-RS-ResourceId OPTIONAL, -- Cond NonCodebook ... }, periodic SEQUENCE { associatedCSI-RS NZP-CSI-RS-ResourceId OPTIONAL, -- Cond NonCodebook ... } usage ENUMERATED {beamManagement, codebook, nonCodebook, antennaSwitching}, alpha Alpha OPTIONAL, -- Need S p0 INTEGER (-202..24) OPTIONAL, -- Cond Setup pathlossReferenceRS PathlossReferenceRS-Config OPTIONAL, -- Need M srs-PowerControlAdjustmentStates ENUMERATED { sameAsFci2, separateClosedLoop} OPTIONAL, -- Need S ..., [[ pathlossReferenceRSList-r16 SetupRelease { PathlossReferenceRSList- r16} OPTIONAL -- Need M ]], [[ usagePDC-r17 ENUMERATED {true} OPTIONAL, -- Need R availableSlotOffsetList-r17 SEQUENCE (SIZE(1..4)) OF AvailableSlotOffset-r17 OPTIONAL, -- Need R followUnifiedTCIstateSRS-r17 ENUMERATED {enabled} OPTIONAL -- Need R ]] } An SRS resource set is configurable. For ap-SRS, the slot offset is configured by the higher-layer parameter slotOffset and sets the delay from the PDCCH trigger reception to the start of the SRS transmission. The resource usage, which is configured by the higher-layer parameter usage sets constraints and assumptions on the resource properties (see 3GPP TS 38.214 for further details). SRS resource sets may be configured with one of four different usages: antennaSwitching, codebook, nonCodebook, or beamManagement. An SRS resource set that is configured with usage antennaSwitching is used for reciprocity-based DL precoding (i.e., used to sound the channel in the UL so that the network node may use reciprocity to set a suitable DL precoders). The WD is expected to transmit one SRS port per WD antenna port. An SRS resource set that is configured with usage codebook is used for CB-based UL transmission (i.e., used to sound the different WD antennas and help the network node to determine/signal a suitable UL precoder, transmission rank, and MCS for PUSCH transmission). There are up to two SRS resources in an SRS resource set with usage codebook. How SRS ports are mapped to WD antenna ports is, however, up to WD implementation and not known to the network node. An SRS resource set that is configured with usage nonCodebook is used for non- codebook (NCB)-based UL transmission. Specifically, the WD transmits one SRS resource per candidate beam (suitable candidate beams are determined by the WD based on CSI-reference signal (RS) measurements in the DL and, hence, reciprocity needs to hold). The network node may then, by indicating a subset of these SRS resources, determine which UL beam(s) that the WD should apply for PUSCH transmission. One UL layer will be transmitted per indicated SRS resource. Note that how the WD maps SRS ports to antenna ports is up to WD implementation and not known to the network node. An SRS resource set that is configured with usage beamManagement is used (mainly for frequency bands above 6 GHz (i.e., for FR2)) to evaluate different WD analog beams (e.g., panels). The WD transmits one SRS resource per analog beam, and the network node will perform a reference signal received power (RSRP) measurement per transmitted SRS resource and, in this way, determine a suitable WD beam that is reported to the WD. The associated channel state information reference signal (CSI-RS) (this configuration is only applicable for NCB-based UL transmission) for each of the possible resource types. For ap-SRS, the associated CSI-RS resource is determined by the higher-layer parameter csi-RS. For p-SRS/sp-SRS, the associated CSI-RS resource is determined by the higher- layer parameter associatedCSI-RS. The PC parameters, e.g., alpha and p0 are used for setting the SRS transmission power. SRS has its own UL PC scheme in NR (see 3GPP TS 38.213 for further details), which specifies how the WD should split the available output power between two or more SRS ports during one SRS transmit occasion (an SRS transmit occasion is a time window within a slot where SRS transmission is performed). SRS resource configuration Each SRS resource is configured with the following in RRC (see below ASN code from 3GPP TS 38.331 version 17.2.0): SRS-Resource ::= SEQUENCE { srs-ResourceId SRS-ResourceId, nrofSRS-Ports ENUMERATED {port1, ports2, ports4}, ptrs-PortIndex ENUMERATED {n0, n1 } OPTIONAL, -- Need R transmissionComb CHOICE { n2 SEQUENCE { combOffset-n2 INTEGER (0..1), cyclicShift-n2 INTEGER (0..7) }, n4 SEQUENCE { combOffset-n4 INTEGER (0..3), cyclicShift-n4 INTEGER (0..11) } resourceMapping SEQUENCE { startPosition INTEGER (0..5), nrofSymbols ENUMERATED {n1, n2, n4}, repetitionFactor ENUMERATED {n1, n2, n4} }, freqDomainPosition INTEGER (0..67), freqDomainShift INTEGER (0..268), freqHopping SEQUENCE { c-SRS INTEGER (0..63), b-SRS INTEGER (0..3), b-hop INTEGER (0..3) }, groupOrSequenceHopping ENUMERATED { neither, groupHopping, sequenceHopping }, resourceType CHOICE { aperiodic SEQUENCE { ... }, semi-persistent SEQUENCE { periodicityAndOffset-sp SRS-PeriodicityAndOffset, ... }, periodic SEQUENCE { periodicityAndOffset-p SRS-PeriodicityAndOffset, ... } sequenceId INTEGER (0..1023), spatialRelationInfo SRS-SpatialRelationInfo OPTIONAL, -- Need R ..., [[ resourceMapping-r16 SEQUENCE { startPosition-r16 INTEGER (0..13), nrofSymbols-r16 ENUMERATED {n1, n2, n4}, repetitionFactor-r16 ENUMERATED {n1, n2, n4} } OPTIONAL - - Need ]], [[ spatialRelationInfo-PDC-r17 SetupRelease { SpatialRelationInfo-PDC- r17 } OPTIONAL, -- Need M resourceMapping-r17 SEQUENCE { startPosition-r17 INTEGER (0..13), nrofSymbols-r17 ENUMERATED {n1, n2, n4, n8, n10, n12, n14}, repetitionFactor-r17 ENUMERATED {n1, n2, n4, n5, n6, n7, n8, n10, n12, n14} } OPTIONAL, - - Need partialFreqSounding-r17 SEQUENCE { startRBIndexFScaling-r17 CHOICE{ startRBIndexAndFreqScalingFactor2-r17 INTEGER (0..1), startRBIndexAndFreqScalingFactor4-r17 INTEGER (0..3) }, enableStartRBHopping-r17 ENUMERATED {enable} OPTIONAL -- Need R } OPTIONAL, - - Need transmissionComb-n8-r17 SEQUENCE { combOffset-n8-r17 INTEGER (0..7), cyclicShift-n8-r17 INTEGER (0..5) } OPTIONAL, - - Need srs-TCIState-r17 CHOICE { srs-UL-TCIState-r17 TCI-UL-State-Id-r17, srs-DLorJoint-TCIState-r17 TCI-StateId } OPTIONAL - - Need ]] } An SRS resource is configurable with respect to, e.g.: ^ The number of SRS ports (1, 2, or 4), configured by the higher-layer parameter nrofSRS-Ports; ^ The transmission comb (i.e., mapping to every 2nd or 4th subcarrier), configured by the higher-layer parameter transmissionComb, which includes: o The comb offset, configured by the higher-layer parameter combOffset, is specified (i.e., which of the combs that should be used); o The cyclic shift (CS), configured by the higher-layer parameter cyclicShift, that configures a (port-specific, for multi-port SRS resources) CS for the Zadoff-Chu sequence that is used for SRS. The use of CSs allows multiplexing of SRS ports on a same comb offset, but there is a limit on how many CSs that may be used per comb offset (8 for comb 2 and 12 for comb 4); o The time-domain position within a given slot, configured with the higher- layer parameter resourceMapping, which includes: ^ The time-domain start position, which is limited to be one of the last 6 symbols, configured by the higher-layer parameter startPosition; ^ The number of symbols for the SRS resource (that may be set to 1, 2 or 4), configured by the higher-layer parameter nrofSymbols; and ^ The repetition factor (that may be set to 1, 2 or 4) configured by the higher-layer parameter repetitionFactor. When the repetition factor is larger than 1, the same frequency resources are used multiple times across symbols, to improve the coverage as this allows more energy to be collected by the receiver. The sounding bandwidth, frequency-domain position and shift, and frequency- hopping pattern of an SRS resource (i.e., which part of the transmission bandwidth that is occupied by the SRS resource) is set through the higher-layer parameters freqDomainPosition, freqDomainShift, and the freqHopping parameters c-SRS, b-SRS, and b-hop. The smallest possible sounding bandwidth is 4 RBs. The higher-layer parameter resourceType determines whether the SRS resource is transmitted as periodic, aperiodic (singe transmission triggered by DCI), or semi persistent (same as periodic except for the start and stop of the periodic transmission is controlled through MAC-CE signaling instead of RRC signaling). The higher-layer parameter sequenceId specifies how the SRS sequence is initialized. The higher-layer parameter spatialRelationInfo configures the spatial relation for the SRS beam with respect to another RS (which could be another SRS, a synchronization signal block (SSB) or a CSI-RS). If an SRS resource has a spatial relation to another SRS resource, then this SRS resource should be transmitted with the same beam (i.e., virtualization) as the indicated SRS resource. In NR 3GPP Technical Release 17 (3GPP Rel-17), transmission comb 8 is supported for which the number of CSs per comb offset is 6 (see higher-layer parameter transmissionComb-n8-r17). In NR 3GPP Rel-16, an SRS resource may occupy any of the 14 symbols in a slot but the number of symbols per SRS resource is limited to 4 (see higher-layer parameter resourceMapping-r16). In NR 3GPP Rel-17, an SRS the number of symbols per SRS resource is up to 14 (see higher-layer parameter resourceMapping-r17). An illustration of how an SRS resource could be allocated in time and frequency within a slot (note that semi-persistent/periodic SRS resources typically span several slots), is provided in FIG.1 for NR 3GPP Rel-15/Rel-16. SRS antenna switching It is desirable for the network node to sound all WD antennas (where sounding an antenna implies that SRS is transmitted from that antenna) but costly to equip the WD with many transmit (Tx) chains. Therefore, SRS antenna switching was introduced in NR 3GPP Rel-15 for WDs equipped with more receive (Rx) chains than Tx chains. If a WD support antenna switching, it will report so by means of WD-capability signaling (see, e.g., Table 1, copied from 3GPP TS 38.306). Table 1 SRS antenna-switching capabilities supported by the WD. supportedSRS-TxPortSwitch supportedSRS-TxPortSwitch-v1610 t1r2 t1r1-t1r2 t1r4 t1r1-t1r2-t1r4 t2r4 t1r1-t1r2-t2r2-t2r4 t2r2 t1r1-t2r2 t4r4 t1r1-t2r2-t4r4 t1r4-t2r4 t1r1-t1r2-t2r2-t1r4-t2r4 The left column in Table 1 lists WD capabilities for SRS antenna-switching that may be reported by a WD in NR 3GPP Rel-15. For example, if a WD reports t1r2 it means that it has two receive (Rx) antennas (i.e., it has two Rx chains) but only has the possibility of transmitting from one of those antennas at a time (i.e., it has one Tx chain). In this case, two single-port SRS resources may be configured for the WD such that it may sound both Rx ports using a Tx transmit port with an antenna switch in between. In NR 3GPP Rel-16, additional WD capabilities for SRS antenna-switching were introduced, which are shown in the right column of Table 1. Here, the WD may indicate support for sounding only a subset of Rx antennas, which may save WD power consumption and SRS overhead at the cost of reduced channel knowledge at the network node. For example, the WD capability t1r1-t1r2 indicates that the network node may configure one single-port SRS resource (no antenna switching) or two single-port SRS resources (same as for the capability t1r2 described above) per SRS resource set with usage antennaSwitching. In NR 3GPP Rel-17, antenna switching was extended to up to 6 or 8 Rx ports, and 1, 2, or 4 Tx chains. The WD may indicate support for antenna-switching configurations beyond 4 Rx via higher-layer parameter srs-AntennaSwitchingBeyond4RX-r17 (see 3GPP TS 38.306 for further details). SRS coverage Schemes to improve the coverage of SRS have been adopted in NR, including repetition of an SRS resource and/or frequency hopping. Before explaining these two schemes, FIG.2, for reference, is an example of SRS transmission without frequency hopping and/or repetition. Here, the entire SRS bandwidth is sounded in a single symbol. An example of SRS frequency hopping is provided in FIG.3. Here, different parts of the SRS bandwidth are sounded in each of four different OFDM symbols, which means that the power spectral density (PSD) for SRS will improve (by four times compared to the baseline case in FIG.2), at the cost of more symbols being used for SRS and a shorter SRS sequence length per OFDM symbol. An example of SRS repetition is provided in FIG.4. Here, one SRS resource is repeated in four consecutive OFDM symbols, which means that the PSD for SRS will improve (by four times compared to the baseline case in FIG.2), at the cost of more symbols being used for SRS and decreased SRS (multiplexing) capacity. It is worth pointing out that SRS repetition and frequency hopping may be used together and for p-SRS/sp-SRS, the frequency-hopping pattern continues beyond the slot boundary. For ap-SRS, on the other hand, all parts of the configured bandwidth must be sounded within a slot. To illustrate these two points, FIG.5 shows a p-SRS resource (with periodicity one) over two adjacent UL slots. Here, the frequency-hopping configuration is the same as in FIG.3, the repetition factor is 2, and the number of SRS symbols per slot is 4. Note that in this example (and in all the previous examples) all hops (highlighted in blue in the figure(s)) belong to the same SRS resource. SRS capacity Schemes to improve SRS capacity (i.e., the number of SRS ports that may be multiplexed onto a limited set of time-and-frequency resources) have been adopted in NR, which include using transmission comb 2, 4 or 8 (i.e., sounding only every 2nd, 4th, or 8th subcarrier within the configured bandwidth), and multiplexing several SRS ports onto the same transmission comb by using different CSs. FIG.6 illustrates how 2 or 4 single-port SRS resources may be multiplexed onto the same configured SRS bandwidth by using transmission comb 2 and 4, respectively. Here, the different SRS resources have been configured with different comb offsets (i.e., RRC-configured with different values of the parameter combOffset). In FIG.6, 2 and 4 single-port SRS resources (with varying comb offset) are multiplexed using transmission comb 2 and 4, respectively. The SRS base sequences, which are used in NR, are such that they are pairwise orthogonal under CSs. Utilizing this property, it is possible to multiplex several SRS ports onto the same transmission comb by using different CSs (and the same base sequence) for different SRS ports. The maximum number of CSs is 8, 12, and 6 for transmission comb 2, 4, and 8, respectively. For multi-port SRS resources, the different SRS ports belonging to the same SRS resource will be configured with a port-specific CS per SRS port. Furthermore, for four-port SRS resources, it is possible (or required, for the case of transmission comb 8) to use up to two different transmission combs (with two SRS ports and, hence, two CSs per comb). FIG.7 is a discrete-time domain representation (after computing an inverse discrete Fourier transform (IDFT)), the (absolute value of the) correlation between a cyclically shifted base sequence and the corresponding non-shifted base sequence. Here, the transmission comb is 2 (such that the maximum number of CSs is 8) and the sequence length is 48 (which corresponds to an SRS transmission spanning 8 resource blocks (RBs)). As shown in FIG 7, the sequences are orthogonal and, hence, may be separated by means of simple signal processing (e.g., through time-domain windowing). In FIG.7, the sequence length is 48 samples, and the maximum number of CSs is 8 (transmission comb is 2). There are, however, drawbacks with increasing the SRS capacity by using a higher transmission comb and/or using larger number of CSs. FIGS.8 and 9 are examples of how the (absolute value of the) correlation in FIG.7 is affected when the SRS is transmitted over a frequency-selective channel, i.e., a channel with a non-zero delay spread (in FIGS. 8 and 9, the delay spread is 15 discrete samples long). Note that the orthogonality between the SRS sequences is lost due to the frequency-selective channel. Further note that increasing the number of (used) CS results in more interference (compare the upper and lower part of the figure). Assuming perfect synchronization, the maximum channel delay spread for which there is no interference is inversely proportional to the product of the subcarrier spacing, the transmission comb, and number of (occupied, and uniformly separated) CSs. In FIGS.8 and 9, the sequence length is 48 samples, and the maximum number of CSs is 8 (transmission comb is 2). In FIG.8, 4 equidistant SRS ports (i.e., CSs) are multiplexed on a same comb offset. In FIG.9, 8 equidistant SRS ports (i.e., CSs) are multiplexed on a same comb offset. In NR 3GPP Rel-18, to support WDs equipped with 8 Tx chains, the maximum number of ports per SRS resource will be increased from 4 (in legacy NR) to 8 for SRS resources in an SRS resource set with usage ‘codebook’ or ‘antennaSwitching’. During the RAN1#110bis-e meeting, it was agreed that all 8 ports of said resources may be mapped to onto each of ^^ symbols, where ^^ ∈ ^1, 2, 4, 8, 10, 12, 14^. During the RAN1#111 meeting, to improve SRS coverage, it was additionally agreed that TDM will be supported for 8-port SRS resources. Specifically, the following agreement was reached: --- Agreement For single SRS resource in an SRS resource set with usage ‘codebook’ for 8Tx PUSCH or ‘antennaSwitching’ (i.e., for 8T8R antenna switching), when the SRS resource is configured with 8 ports and m OFDM symbols (m > 1), support the case of 8 ports mapped onto the m OFDM symbols Option 1: Different SRS ports are mapped onto different OFDM symbols (i.e., TDM) FFS: m may be legacy values, i.e., 2,4,[8,10,12,14]. ---- According to the above agreement, only a subset of the 8 SRS ports will be transmitted in each of the ^^ symbols, ^^ ∈ ^1, 2, ^8, 10, 12, 14^^. However, it is unclear how the SRS ports will be split over the ^^ symbols. Furthermore, it is unclear how to map the subset of SRS ports of an 8-port SRS resource to comb offsets and cyclic shifts in each of the ^^ symbols. SUMMARY Some embodiments advantageously provide methods, network nodes and wireless devices for time division multiplexing (TDM) for eight port sounding reference signals (SRS). Some embodiments may provide configuration, signaling, restrictions and rules for SRS TDM, including formulas for mapping SRS ports to cyclic shifts and comb offsets. Some embodiments provide for associating a subset of SRS ports in an 8-port SRS resource with a subset of configured SRS symbols. In some embodiments, mapping may be such that number of SRS ports and symbols is the same for each subset): ^ The subsets of SRS ports are non-overlapping. The number of SRS ports over all subsets may be equal to the configured number of SRS ports; and/or ^ The subsets of SRS symbols are non-overlapping. The number of symbols over all subsets may be smaller than or equal to the configured number of SRS symbols. In some embodiments, the SRS ports may be mapped to SRS symbols according to: ^ Sequential mapping pattern; and/or ^ Cyclical mapping pattern. In some embodiments, the SRS ports within each subset are mapped to comb offset and cyclic shifts according to a mapping rule such that: ^ The same set of comb offsets and cyclic shifts are used for all subsets; or ^ The set of comb offsets and cyclic shifts over all subsets are the same as the set of comb offsets and cyclic shifts for an SRS resource not configured with TDM. Some embodiments provide configurations of TDM for SRS, which may improve SRS coverage for SRS resources spanning different numbers of symbols. Some embodiments provide a configuration of TDM together with legacy SRS coverage- enhancement schemes (i.e., repetition, frequency hopping, resource block level partial frequency sounding (RPFS)). According to one aspect, a method in a network node configured to communicate with a wireless device, WD, is provided. The method includes configuring the WD with cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped. The method also includes configuring the WD to perform SRS transmissions according to the cyclical mapping. According to one aspect, in some embodiments, a number of SRS ports in a subset of SRS ports of the N subsets is a ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^, the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ^^ୟ ୗ ୮ୖୗ denotes a number of SRS ports per SRS resource and ^^^ୈ^ is a TDM factor equal to N. In some embodiments, ^^^ୈ^ is equal to 2 when TDM is configured and ^^^ୈ^ is equal to 1, otherwise. In some embodiments, only combinations of ^^^ ୗ ^ୖ ୫ୗ ୠ and ^^^ୈ^ that result in a ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, being an integer are configured, where ^^^ ୗ ^ୖ ୫ୗ ୠ is equal to M and is radio resource control, RRC, configured . In some embodiments, the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, being greater than 1 is allowed only when an SRS resource is configured with one or more of repetition, frequency hopping and RPFS. In some embodiments, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then the nearest integer less than the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ is a number of SRS symbols per subset of SRS ports. In some embodiments, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then a number of symbols per subset of SRS ports varies over the N subsets of SRS ports. In some embodiments, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then a number of symbols and a number of SRS ports per subset of SRS ports varies over the N subset of ports. In some embodiments, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is greater than 1 and repetition, frequency hopping and RPFS are not configured, then ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^ SRS ports per subset of SRS symbols are repeated over ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, OFDM symbols. In some embodiments, the method includes configuring the WD to transmit a repetition of ^^ୟ ୗ ୮ୖୗ SRS ports in each of a plurality of successive sets of ^^^ୈ^ symbols. In some embodiments, the method includes configuring the WD to sound SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured. In some embodiments, a same set of comb offsets and cyclic shifts, CS, are occupied by each subset of SRS ports. In some embodiments, a comb offset for an antenna port is based at least in part on the ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^. In some embodiments, a cyclic shift for an antenna port is based at least in part on the ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^. In some embodiments, when an 8 port SRS resource is configured with both TDM and cyclic-shift hopping or with both TDM and comb-offset hopping, then a hopping pattern for each subset of an number ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^ of SRS ports is a same hopping pattern for a ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^ port SRS resource. According to another aspect, a method in a wireless device, WD, configured to communicate with a network node, is provided. The method includes receiving from the network node cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped. The method also includes cyclically mapping the N subsets of SRS ports to the M OFDM symbols. The method further includes performing SRS transmissions according to the cyclical mapping. According to this aspect, in some embodiments, a number of SRS ports in a subset of SRS ports of the N subsets is a ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^, the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ^^ୟ ୗ ୮ୖୗ denotes a number of SRS ports per SRS resource and ^^^ୈ^ is a TDM factor equal to N. In some embodiments, the method includes transmitting a repetition of ^^ୟ ୗ ୮ୖୗ SRS ports in each of a plurality of successive sets of ^^^ୈ^ symbols. In some embodiments, the method includes sounding SRS ports in a subset of SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured. In some embodiments, when time division multiplexing and frequency hopping are both configured, using a same frequency counter to determine a frequency domain position for all subsets of SRS ports. According to yet another aspect, a network node configured to communicate with a wireless device, WD, is provided. The network node is configured to configure the WD with cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped. The network node is also configured to configure the WD to perform SRS transmissions according to the cyclical mapping. According to this aspect, in some embodiments, a number of SRS ports in a subset of SRS ports of the N subsets is a ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^, the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ^^ୟ ୗ ୮ୖୗ denotes a number of SRS ports per SRS resource and ^^^ୈ^ is a TDM factor equal to N. In some embodiments, ^^^ୈ^ is equal to 2 when TDM is configured and ^^^ୈ^ is equal to 1, otherwise. In some embodiments, only combinations of ^^^ ୗ ^ୖ ୫ୗ ୠ and ^^^ୈ^ that result in a ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, being an integer are configured, where ^^^ ୗ ^ୖ ୫ୗ ୠ is equal to M and is radio resource control, RRC, configured. In some embodiments, the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, being greater than 1 is allowed only when an SRS resource is configured with one or more of repetition, frequency hopping and RPFS. In some embodiments, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then the nearest integer less than the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ is a number of symbols per subset of SRS ports. In some embodiments, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then a number of symbols per subset of SRS ports varies over the N subsets of SRS ports. In some embodiments, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then a number of symbols and a number of SRS ports per subset of SRS ports varies over the N subset of ports. In some embodiments, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is greater than 1 and repetition, frequency hopping and RPFS are not configured, then ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^ SRS ports per subset of SRS symbols are repeated over ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, OFDM symbols. In some embodiments, the network node is configured to configure the WD to transmit a repetition of ^^ୟ ୗ ୮ୖୗ SRS ports in each of a plurality of successive sets of ^^^ୈ^ symbols. In some embodiments, the network node is configured to configure the WD to sound SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured. In some embodiments, a same set of comb offsets and cyclic shifts, CS, are occupied by each subset of SRS ports. In some embodiments, a comb offset for an antenna port is based at least in part on the ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^. In some embodiments, a cyclic shift for an antenna port is based at least in part on the ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^. In some embodiments, when an 8 port SRS resource is configured with both TDM and cyclic shifts or both TDM and comb- offset hopping, then a hopping pattern for each subset of an number P of SRS ports is a same hopping pattern for a P port SRS resource. According to another aspect, a WD configured to communicate with a network node, is provided. The WD is configured to receive from the network node cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped. The WD is configured to cyclically map the N subsets of SRS ports to the M OFDM symbols. The WD is also configured to perform SRS transmissions according to the cyclical mapping. In some embodiments, a number of SRS ports in a subset of SRS ports of the N subsets is based on a ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^, the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ^^ୟ ୗ ୮ୖୗ denotes a number of SRS ports per SRS resource and ^^^ୈ^ is a TDM factor equal to N. In some embodiments, the WD is configured to transmit a repetition of ^^ୟ ୗ ୮ୖୗ SRS ports in each of a plurality of successive sets of ^^^ୈ^ symbols. In some embodiments, the WD is configured to sound SRS ports in a subset of SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured. In some embodiments, when time division multiplexing and frequency hopping are both configured, using a same frequency counter to determine a frequency domain position for all subsets of SRS ports. BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein: FIG.1 is an example of SRS resource allocation; FIG.2 illustrates SRS transmission without frequency hopping or repetition; FIG.3 illustrates SRS transmission with frequency hopping; FIG.4 illustrates SRS transmission with repetition; FIG.5 illustrates SRS transmission over two adjacent UL slots; FIG.6 illustrates 2 and 4 multiplexed single port SRS resources; FIG.7 illustrates correlation between cyclically shifted SRS base sequences with corresponding unshifted base sequence (for sequence length of 48 samples and a maximum of cyclic shift of 8); FIG.8 illustrates correlation between cyclically shifted SRS base sequences which have been transmitted over a frequency-selective channel, with the corresponding non- shifted base sequence, for 4 equidistant SRS ports; FIG.9 illustrates correlation between cyclically shifted SRS base sequences which have been transmitted over a frequency-selective channel, with the corresponding non- shifted base sequence, for 8 equidistant SRS ports; FIG.10 is a schematic diagram of an example network architecture illustrating a communication system connected via an intermediate network to a host computer according to the principles in the present disclosure; FIG.11 is a block diagram of a host computer communicating via a network node with a wireless device over an at least partially wireless connection according to some embodiments of the present disclosure; FIG.12 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for executing a client application at a wireless device according to some embodiments of the present disclosure; FIG.13 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for receiving user data at a wireless device according to some embodiments of the present disclosure; FIG.14 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for receiving user data from the wireless device at a host computer according to some embodiments of the present disclosure; FIG.15 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for receiving user data at a host computer according to some embodiments of the present disclosure; FIG.16 is a flowchart of an example process in a network node for time division multiplexing (TDM) for eight port sounding reference signals (SRS); FIG.17 is a flowchart of an example process in a WD for time division multiplexing (TDM) for eight port sounding reference signals (SRS); FIG.18 is a flowchart of another example process in a network node for time division multiplexing (TDM) for eight port sounding reference signals (SRS); FIG.19 is a flowchart of another example process in a WD for time division multiplexing (TDM) for eight port sounding reference signals (SRS); FIG.20 illustrates SRS TDM combined with SRS repetition; FIG.21 illustrates SRS TDM combined with SRS frequency hopping over two hops; FIG.22 illustrates SRS TDM combined with SRS frequency hopping over four hops; FIG.23 is an example of SRS TDM when a number of SRS ports per subset of SRS symbols is 4, the number of SRS symbols is 8, the repetition factor is 4 and intra-slot hopping is not configured; and FIG.24 illustrates SRS TDM combined with SRS frequency hopping over two hops with alternative mapping. DETAILED DESCRIPTION Before describing in detail example embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to time division multiplexing (TDM) for eight port sounding reference signals (SRS). Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Like numbers refer to like elements throughout the description. As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the art will appreciate that multiple components may interoperate and modifications and variations are possible of achieving the electrical and data communication. In some embodiments described herein, the term “coupled,” “connected,” and the like, may be used herein to indicate a connection, although not necessarily directly, and may include wired and/or wireless connections. The term “network node” used herein may be any kind of network node comprised in a radio network which may further comprise any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multi- standard radio (MSR) radio node such as MSR BS, multi-cell/multicast coordination entity (MCE), integrated access and backhaul (IAB) node, relay node, donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3rd party node, a node external to the current network), nodes in distributed antenna system (DAS), a spectrum access system (SAS) node, an element management system (EMS), etc. The network node may also comprise test equipment. The term “radio node” used herein may be used to also denote a wireless device (WD) such as a wireless device (WD) or a radio network node. In some embodiments, the non-limiting terms wireless device (WD) or a user equipment (UE) are used interchangeably. The WD herein may be any type of wireless device capable of communicating with a network node or another WD over radio signals, such as wireless device (WD). The WD may also be a radio communication device, target device, device to device (D2D) WD, machine type WD or WD capable of machine to machine communication (M2M), low-cost and/or low-complexity WD, a sensor equipped with WD, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (IoT) device, or a Narrowband IoT (NB-IOT) device, etc. Also, in some embodiments the generic term “radio network node” is used. It may be any kind of a radio network node which may comprise any of base station, radio base station, base transceiver station, base station controller, network controller, RNC, evolved Node B (eNB), Node B, gNB, Multi-cell/multicast Coordination Entity (MCE), IAB node, relay node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH). Note that although terminology from one particular wireless system, such as, for example, 3GPP LTE and/or New Radio (NR), may be used in this disclosure, this should not be seen as limiting the scope of the disclosure to only the aforementioned system. Other wireless systems, including without limitation Wide Band Code Division Multiple Access (WCDMA), Worldwide Interoperability for Microwave Access (WiMax), Ultra Mobile Broadband (UMB) and Global System for Mobile Communications (GSM), may also benefit from exploiting the ideas covered within this disclosure. Note further, that functions described herein as being performed by a wireless device or a network node may be distributed over a plurality of wireless devices and/or network nodes. In other words, it is contemplated that the functions of the network node and wireless device described herein are not limited to performance by a single physical device and, in fact, may be distributed among several physical devices. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Some embodiments provide time division multiplexing (TDM) for eight port sounding reference signals (SRS). Returning now to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG.10 a schematic diagram of a communication system 10, according to an embodiment, such as a 3GPP-type cellular network that may support standards such as LTE and/or NR (5G), which comprises an access network 12, such as a radio access network, and a core network 14. The access network 12 comprises a plurality of network nodes 16a, 16b, 16c (referred to collectively as network nodes 16), such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 18a, 18b, 18c (referred to collectively as coverage areas 18). Each network node 16a, 16b, 16c is connectable to the core network 14 over a wired or wireless connection 20. A first wireless device (WD) 22a located in coverage area 18a is configured to wirelessly connect to, or be paged by, the corresponding network node 16a. A second WD 22b in coverage area 18b is wirelessly connectable to the corresponding network node 16b. While a plurality of WDs 22a, 22b (collectively referred to as wireless devices 22) are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole WD is in the coverage area or where a sole WD is connecting to the corresponding network node 16. Note that although only two WDs 22 and three network nodes 16 are shown for convenience, the communication system may include many more WDs 22 and network nodes 16. Also, it is contemplated that a WD 22 may be in simultaneous communication and/or configured to separately communicate with more than one network node 16 and more than one type of network node 16. For example, a WD 22 may have dual connectivity with a network node 16 that supports LTE and the same or a different network node 16 that supports NR. As an example, WD 22 may be in communication with an eNB for LTE/E-UTRAN and a gNB for NR/NG-RAN. The communication system 10 may itself be connected to a host computer 24, which may be embodied in the hardware and/or software of a standalone server, a cloud- implemented server, a distributed server or as processing resources in a server farm. The host computer 24 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. The connections 26, 28 between the communication system 10 and the host computer 24 may extend directly from the core network 14 to the host computer 24 or may extend via an optional intermediate network 30. The intermediate network 30 may be one of, or a combination of more than one of, a public, private or hosted network. The intermediate network 30, if any, may be a backbone network or the Internet. In some embodiments, the intermediate network 30 may comprise two or more sub-networks (not shown). The communication system of FIG.10 as a whole enables connectivity between one of the connected WDs 22a, 22b and the host computer 24. The connectivity may be described as an over-the-top (OTT) connection. The host computer 24 and the connected WDs 22a, 22b are configured to communicate data and/or signaling via the OTT connection, using the access network 12, the core network 14, any intermediate network 30 and possible further infrastructure (not shown) as intermediaries. The OTT connection may be transparent in the sense that at least some of the participating communication devices through which the OTT connection passes are unaware of routing of uplink and downlink communications. For example, a network node 16 may not or need not be informed about the past routing of an incoming downlink communication with data originating from a host computer 24 to be forwarded (e.g., handed over) to a connected WD 22a. Similarly, the network node 16 need not be aware of the future routing of an outgoing uplink communication originating from the WD 22a towards the host computer 24. A network node 16 is configured to include an SRS unit 32 which may be configured to associate a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols, the associating being according to one of a sequential mapping pattern and a cyclical mapping pattern. Alternatively or in addition, the SRS unit 32 may be configured to configure the WD 22 with cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols. A wireless device 22 is configured to include a determination unit 34 which may be configured to determine the subset of SRS symbols based on a received mapping configuration. Alternatively or in addition, the determination unit 34 may be configured to cyclically map N subsets of SRS ports to M OFDM symbols Example implementations, in accordance with an embodiment, of the WD 22, network node 16 and host computer 24 discussed in the preceding paragraphs will now be described with reference to FIG.11. In a communication system 10, a host computer 24 comprises hardware (HW) 38 including a communication interface 40 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system 10. The host computer 24 further comprises processing circuitry 42, which may have storage and/or processing capabilities. The processing circuitry 42 may include a processor 44 and memory 46. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 42 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 44 may be configured to access (e.g., write to and/or read from) memory 46, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory). Processing circuitry 42 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by host computer 24. Processor 44 corresponds to one or more processors 44 for performing host computer 24 functions described herein. The host computer 24 includes memory 46 that is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 48 and/or the host application 50 may include instructions that, when executed by the processor 44 and/or processing circuitry 42, causes the processor 44 and/or processing circuitry 42 to perform the processes described herein with respect to host computer 24. The instructions may be software associated with the host computer 24. The software 48 may be executable by the processing circuitry 42. The software 48 includes a host application 50. The host application 50 may be operable to provide a service to a remote user, such as a WD 22 connecting via an OTT connection 52 terminating at the WD 22 and the host computer 24. In providing the service to the remote user, the host application 50 may provide user data which is transmitted using the OTT connection 52. The “user data” may be data and information described herein as implementing the described functionality. In one embodiment, the host computer 24 may be configured for providing control and functionality to a service provider and may be operated by the service provider or on behalf of the service provider. The processing circuitry 42 of the host computer 24 may enable the host computer 24 to observe, monitor, control, transmit to and/or receive from the network node 16 and or the wireless device 22. The communication system 10 further includes a network node 16 provided in a communication system 10 and including hardware 58 enabling it to communicate with the host computer 24 and with the WD 22. The hardware 58 may include a communication interface 60 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 10, as well as a radio interface 62 for setting up and maintaining at least a wireless connection 64 with a WD 22 located in a coverage area 18 served by the network node 16. The radio interface 62 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers. The communication interface 60 may be configured to facilitate a connection 66 to the host computer 24. The connection 66 may be direct or it may pass through a core network 14 of the communication system 10 and/or through one or more intermediate networks 30 outside the communication system 10. In the embodiment shown, the hardware 58 of the network node 16 further includes processing circuitry 68. The processing circuitry 68 may include a processor 70 and a memory 72. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 68 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 70 may be configured to access (e.g., write to and/or read from) the memory 72, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory). Thus, the network node 16 further has software 74 stored internally in, for example, memory 72, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the network node 16 via an external connection. The software 74 may be executable by the processing circuitry 68. The processing circuitry 68 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by network node 16. Processor 70 corresponds to one or more processors 70 for performing network node 16 functions described herein. The memory 72 is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 74 may include instructions that, when executed by the processor 70 and/or processing circuitry 68, causes the processor 70 and/or processing circuitry 68 to perform the processes described herein with respect to network node 16. For example, processing circuitry 68 of the network node 16 may include an SRS unit 32 which may be configured to associate a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols, the associating being according to one of a sequential mapping pattern and a cyclical mapping pattern. Alternatively or in addition, the SRS unit 32 may be configured to configure the WD 22 with cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols. The communication system 10 further includes the WD 22 already referred to. The WD 22 may have hardware 80 that may include a radio interface 82 configured to set up and maintain a wireless connection 64 with a network node 16 serving a coverage area 18 in which the WD 22 is currently located. The radio interface 82 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers. The hardware 80 of the WD 22 further includes processing circuitry 84. The processing circuitry 84 may include a processor 86 and memory 88. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 84 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 86 may be configured to access (e.g., write to and/or read from) memory 88, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory). Thus, the WD 22 may further comprise software 90, which is stored in, for example, memory 88 at the WD 22, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the WD 22. The software 90 may be executable by the processing circuitry 84. The software 90 may include a client application 92. The client application 92 may be operable to provide a service to a human or non-human user via the WD 22, with the support of the host computer 24. In the host computer 24, an executing host application 50 may communicate with the executing client application 92 via the OTT connection 52 terminating at the WD 22 and the host computer 24. In providing the service to the user, the client application 92 may receive request data from the host application 50 and provide user data in response to the request data. The OTT connection 52 may transfer both the request data and the user data. The client application 92 may interact with the user to generate the user data that it provides. The processing circuitry 84 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by WD 22. The processor 86 corresponds to one or more processors 86 for performing WD 22 functions described herein. The WD 22 includes memory 88 that is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 90 and/or the client application 92 may include instructions that, when executed by the processor 86 and/or processing circuitry 84, causes the processor 86 and/or processing circuitry 84 to perform the processes described herein with respect to WD 22. For example, the processing circuitry 84 of the wireless device 22 may include a determination unit 34 that determines the subset of SRS symbols based on a received mapping configuration. Alternatively or in addition, the determination unit 34 may be configured to cyclically map N subsets of SRS ports to M OFDM symbols In some embodiments, the inner workings of the network node 16, WD 22, and host computer 24 may be as shown in FIG.11 and independently, the surrounding network topology may be that of FIG.10. In FIG.11, the OTT connection 52 has been drawn abstractly to illustrate the communication between the host computer 24 and the wireless device 22 via the network node 16, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from the WD 22 or from the service provider operating the host computer 24, or both. While the OTT connection 52 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network). The wireless connection 64 between the WD 22 and the network node 16 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the WD 22 using the OTT connection 52, in which the wireless connection 64 may form the last segment. More precisely, the teachings of some of these embodiments may improve the data rate, latency, and/or power consumption and thereby provide benefits such as reduced user waiting time, relaxed restriction on file size, better responsiveness, extended battery lifetime, etc. In some embodiments, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 52 between the host computer 24 and WD 22, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 52 may be implemented in the software 48 of the host computer 24 or in the software 90 of the WD 22, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 52 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 48, 90 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 52 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect the network node 16, and it may be unknown or imperceptible to the network node 16. Some such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary WD signaling facilitating the host computer’s 24 measurements of throughput, propagation times, latency and the like. In some embodiments, the measurements may be implemented in that the software 48, 90 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 52 while it monitors propagation times, errors, etc. Thus, in some embodiments, the host computer 24 includes processing circuitry 42 configured to provide user data and a communication interface 40 that is configured to forward the user data to a cellular network for transmission to the WD 22. In some embodiments, the cellular network also includes the network node 16 with a radio interface 62. In some embodiments, the network node 16 is configured to, and/or the network node’s 16 processing circuitry 68 is configured to perform the functions and/or methods described herein for preparing/initiating/maintaining/ supporting/ending a transmission to the WD 22, and/or preparing/terminating/ maintaining/supporting/ending in receipt of a transmission from the WD 22. In some embodiments, the host computer 24 includes processing circuitry 42 and a communication interface 40 that is configured to a communication interface 40 configured to receive user data originating from a transmission from a WD 22 to a network node 16. In some embodiments, the WD 22 is configured to, and/or comprises a radio interface 82 and/or processing circuitry 84 configured to perform the functions and/or methods described herein for preparing/initiating/maintaining/ supporting/ending a transmission to the network node 16, and/or preparing/ terminating/maintaining/supporting/ending in receipt of a transmission from the network node 16. Although FIGS.10 and 11 show various “units” such as SRS unit 32, and determination unit 34 as being within a respective processor, it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, the units may be implemented in hardware or in a combination of hardware and software within the processing circuitry. FIG.12 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIGS.10 and 11, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIG.11. In a first step of the method, the host computer 24 provides user data (Block S100). In an optional substep of the first step, the host computer 24 provides the user data by executing a host application, such as, for example, the host application 50 (Block S102). In a second step, the host computer 24 initiates a transmission carrying the user data to the WD 22 (Block S104). In an optional third step, the network node 16 transmits to the WD 22 the user data which was carried in the transmission that the host computer 24 initiated, in accordance with the teachings of the embodiments described throughout this disclosure (Block S106). In an optional fourth step, the WD 22 executes a client application, such as, for example, the client application 92, associated with the host application 50 executed by the host computer 24 (Block S108). FIG.13 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG.10, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS.10 and 11. In a first step of the method, the host computer 24 provides user data (Block S110). In an optional substep (not shown) the host computer 24 provides the user data by executing a host application, such as, for example, the host application 50. In a second step, the host computer 24 initiates a transmission carrying the user data to the WD 22 (Block S112). The transmission may pass via the network node 16, in accordance with the teachings of the embodiments described throughout this disclosure. In an optional third step, the WD 22 receives the user data carried in the transmission (Block S114). FIG.14 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG.10, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS.10 and 11. In an optional first step of the method, the WD 22 receives input data provided by the host computer 24 (Block S116). In an optional substep of the first step, the WD 22 executes the client application 92, which provides the user data in reaction to the received input data provided by the host computer 24 (Block S118). Additionally or alternatively, in an optional second step, the WD 22 provides user data (Block S120). In an optional substep of the second step, the WD provides the user data by executing a client application, such as, for example, client application 92 (Block S122). In providing the user data, the executed client application 92 may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the WD 22 may initiate, in an optional third substep, transmission of the user data to the host computer 24 (Block S124). In a fourth step of the method, the host computer 24 receives the user data transmitted from the WD 22, in accordance with the teachings of the embodiments described throughout this disclosure (Block S126). FIG.15 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG.10, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS.10 and 11. In an optional first step of the method, in accordance with the teachings of the embodiments described throughout this disclosure, the network node 16 receives user data from the WD 22 (Block S128). In an optional second step, the network node 16 initiates transmission of the received user data to the host computer 24 (Block S130). In a third step, the host computer 24 receives the user data carried in the transmission initiated by the network node 16 (Block S132). FIG.16 is a flowchart of an example process in a network node 16 for time division multiplexing (TDM) for eight port sounding reference signals (SRS). One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 68 (including the SRS unit 32), processor 70, radio interface 62 and/or communication interface 60. Network node 16 such as via processing circuitry 68 and/or processor 70 and/or radio interface 62 and/or communication interface 60 is configured to associate a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols, the associating being according to one of a sequential mapping pattern and a cyclical mapping pattern (Block S134). In some embodiments, SRS ports in the subset of SRS ports are mapped to comb offsets and cyclic shifts according to a mapping rule. In some embodiments, a same set of comb offsets and cyclic shifts are used for all subsets of a plurality of SRS port subsets. In some embodiments, a same set of comb offsets and cyclic shifts over all of subsets of the plurality of SRS port subsets are used for an SRS resource not configured with time division duplexing, TDM. In some embodiments, the one of the sequential mapping pattern and the cyclical mapping pattern is radio resource control, RRC, configured for each SRS resource of a plurality of SRS resources. In some embodiments, when both time division multiplexing, TDM, and frequency hopping are configured, a plurality of SRS ports of the subset of SRS ports are sounded before frequency hopping. In some embodiments, all SRS ports of the subset of SRS ports are sounded within a slot of SRS transmission. In some embodiments, when both time division multiplexing, TDM, and frequency hopping are configured, a same frequency hopping counter is used to determine a frequency domain position for all subsets of SRS ports. FIG.17 is a flowchart of an example process in a WD 22 for time division multiplexing (TDM) for eight port sounding reference signals (SRS). One or more blocks described herein may be performed by one or more elements of WD 22 such as by one or more of processing circuitry 84 (including the determination unit 34), processor 86 and/or radio interface 82. WD 22 such as via processing circuitry 84 and/or processor 86 and/or radio interface 82 is configured to receive a configuration of a one of a sequential mapping pattern and a cyclical mapping pattern for associating a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols (Block S136). The process also includes determining the subset of SRS symbols based on the received configuration (Block S138). In some embodiments, the configuration is received on radio resource control, RRC, signaling. FIG.18 is a flowchart of an example process in a network node 16 for time division multiplexing (TDM) for eight port sounding reference signals (SRS). One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 68 (including the SRS unit 32), processor 70, radio interface 62 and/or communication interface 60. Network node 16 such as via processing circuitry 68 and/or processor 70 and/or radio interface 62 and/or communication interface 60 is configured to configure the WD 22 with cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped (Block S140). The method also includes configuring the WD 22 to perform SRS transmissions according to the cyclical mapping (Block S142). According to one aspect, in some embodiments, a number of SRS ports in a subset of SRS ports of the N subsets is a ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^, the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ^^ୟ ୗ ୮ୖୗ denotes a number of SRS ports per SRS resource and ^^^ୈ^ is a TDM factor equal to N. In some embodiments, ^^^ୈ^ is equal to 2 when TDM is configured and ^^^ୈ^ is equal to 1, otherwise. In some embodiments, only combinations of ^^^ ୗ ^ୖ ୫ୗ ୠ and ^^^ୈ^ that result in a ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, being an integer are configured, where ^^^ ୗ ^ୖ ୫ୗ ୠ is equal to M and is radio resource control, RRC, configured . In some embodiments, the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, being greater than 1 is allowed only when an SRS resource is configured with one or more of repetition, frequency hopping and RPFS. In some embodiments, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then the nearest integer less than the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ is a number of SRS symbols per subset of SRS ports. In some embodiments, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then a number of symbols per subset of SRS ports varies over the N subsets of SRS ports. In some embodiments, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then a number of symbols and a number of SRS ports per subset of SRS ports varies over the N subset of ports. In some embodiments, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is greater than 1 and repetition, frequency hopping and RPFS are not configured, then ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^ SRS ports per subset of SRS symbols are repeated over ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, OFDM symbols. In some embodiments, the method includes configuring the WD 22 to transmit a repetition of ^^ୟ ୗ ୮ୖୗ SRS ports in each of a plurality of successive sets of ^^^ୈ^ symbols. In some embodiments, the method includes configuring the WD 22 to sound SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured. In some embodiments, a same set of comb offsets and cyclic shifts, CS, are occupied by each subset of SRS ports. In some embodiments, a comb offset for an antenna port is based at least in part on the ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^. In some embodiments, a cyclic shift for an antenna port is based at least in on the ratio, ^^ୗୖୗ/ ^^ . In some embodiments, when an 8 ୟ୮ ^ୈ^ port SRS resource is configured with TDM and cyclic-shift hopping or with both TDM and comb-offset hopping, then a hopping pattern for each subset of an number ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^ of SRS ports is a same hopping pattern for a ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^ port SRS resource. FIG.19 is a flowchart of an example process in a WD 22 for time division multiplexing (TDM) for eight port sounding reference signals (SRS). One or more blocks described herein may be performed by one or more elements of WD 22 such as by one or more of processing circuitry 84 (including the determination unit 34), processor 86 and/or radio interface 82. WD 22 such as via processing circuitry 84 and/or processor 86 and/or radio interface 82 is configured to receive from the network node 16 cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped (Block S144). The method also includes cyclically mapping the N subsets of SRS ports to the M OFDM symbols (Block S146). The method further includes performing SRS transmissions according to the cyclical mapping (Block S148). According to this aspect, in some embodiments, a number of SRS ports in a subset of SRS ports of the N subsets is a ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^, the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ^^ୟ ୗ ୮ୖୗ denotes a number of SRS ports per SRS resource and ^^^ୈ^ is a TDM factor equal to N. In some embodiments, the method includes transmitting a repetition of ^^ୟ ୗ ୮ୖୗ SRS ports in each of a plurality of successive sets of ^^^ୈ^ symbols. In some embodiments, the method includes sounding SRS ports in a subset of SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured. In some embodiments, when time division multiplexing and frequency hopping are both configured, using a same frequency counter to determine a frequency domain position for all subsets of SRS ports. Having described the general process flow of arrangements of the disclosure and having provided examples of hardware and software arrangements for implementing the processes and functions of the disclosure, the sections below provide details and examples of arrangements for time division multiplexing (TDM) for eight port sounding reference signals (SRS). Splitting SRS ports over OFDM symbols How to split SRS ports over OFDM symbols for an 8-port SRS resource configured with TDM is considered. In what follows, ^^^ ୗ ^ୖ ୫ୗ ୠ ൌ ^^ denotes the number of RRC configured SRS symbols ( ^^^ ୗ ^ୖ ୫ୗ ୠ is used in existing NR specifications, e.g., in 3GPP TS 38.211). Furthermore, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^ denotes the (maximum) number of SRS ports per subset of SRS symbols is configured. Here, ^^ୟ ୗ ୮ୖୗ is the number of SRS ports per SRS resource and ^^^ୈ^ is a “TDM factor” (note of “TDM factor”, a different terminology may be used in 3GPP specifications for this parameter). The parameter ^^^ୈ^ will be used in later embodiments to derive the comb offset and CS allocation for an SRS resource configured with TDM. In some embodiments, ^^^ୈ^ ൌ 2 if TDM is configured, e.g., via higher-layer parameter timeDivisionDuplexing-r18 as per the following example in ASN, and ^^^ୈ^ ൌ 1 otherwise. SRS-Resource ::= SEQUENCE { srs-ResourceId SRS-ResourceId, nrofSRS-Ports ENUMERATED {port1, ports2, ports4, ports8}, ... [[ ... timeDivisionDuplexing-r18 ENUMERATED {enabled} OPTIONAL, -- Cond 8Tx ... ]] } In embodiments, the field timeDivisionDuplexing-r18 is present only if the number of SRS ports in the SRS resource is set to 8, e.g., as described in Table 2. Table 2 Conditional presence of timeDivisionDuplexing-r18 field. Conditional presence Explanation The field is optional present if higher-layer parameter 8Tx nrofSRS-Ports is set to ports8. Otherwise, it is absent. In some embodiments, one of ^^^ୈ^ ∈ ^2, 4, 8^ if TDM is configured and ^^^ୈ^ ൌ 1, otherwise. Here, the value of ^^^ୈ^ may be explicitly configured (e.g., as per the following example in abstract syntax notation (ASN)) or may be implicitly derived based on other SRS configuration parameters (e.g., on the number of SRS symbols configured per SRS resource). SRS-Resource ::= SEQUENCE { srs-ResourceId SRS-ResourceId, nrofSRS-Ports ENUMERATED {port1, ports2, ports4, ports8}, ... [[ ... timeDivisionDuplexing-r18 SEQUENCE { nrofSRS-PortsPerSymbol-r18 ENUMERATED {n1, n2, n4} } OPTIONAL, -- Cond 8Tx } ... ]] } Some embodiments In the following embodiments, for an ^^ୟ ୗ ୮ୖୗ-port SRS resource configured with TDM and ^^^ ୗ ^ୖ ୫ୗ ୠ symbols, orthogonal subsets of ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^ SRS ports from the set 1^ will be transmitted in nonoverlapping subsets of the set, െ 1^ of symbols configured for said ^^ୟ ୗ ୮ୖୗ-port SRS resource. embodiments, the only allowed RRC configured combinations of ^^ୗୖୗ ^^୫ୠ and ^^^ୈ^, are those resulting in ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ being an integer: In some embodiments, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ ^ 1 is allowed only if SRS resource is configured with one or more of repetition, frequency hopping, or RPFS. In some embodiments, for example, for ^^ୟ ୗ ୮ୖୗ ൌ 8 and ^^^ୈ^ ൌ 2, only ^^^ ୗ ^ୖ ୫ୗ ୠ ൌ ^^ ൌ 2, 4,8,12 are supported when TDM is configured (i.e., ^^^ ୗ ^ୖ ୫ୗ ୠ ൌ ^^ ൌ 10,14 are not supported). In some embodiments, if ^^^ ୗ ^ୖ ୫ୗ ୠ ^ ^^^ୈ^ and neither of repetition, frequency hopping, or RPFS are configured, the ^^ୟ ୗ ୮ୖୗ⁄ ^^^ୈ^ SRS ports per subset of SRS symbols will be repeated over ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ contiguous OFDM symbols. In other words, SRS repetition does not need to be explicitly configured if SRS TDM is configured, in some embodiments. Sequential mapping In some embodiments, SRS ports 0, … , ^^ୟ ୗ ୮ୖୗ⁄ ^^^ୈ^ െ 1 are transmitted in SRS symbols 0, … , ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ െ 1, SRS ports ^^ୟ ୗ ୮ୖୗ⁄ ^^^ୈ^ , … , 2 ∙ ^^ୟ ୗ ୮ୖୗ⁄ ^^^ୈ^ െ 1 are ^^ , … ,2 ∙ ^^ୗୖୗ / ^^ െ 1, etc. ^ୈ^ ^^୫ୠ ^ୈ^ FIG.20 shows an to the above embodiments (with sequential mapping) for the case when the number of SRS ports per subset of SRS symbols is ^^ୟ ୗ ୮ୖୗ⁄ ^^^ୈ^ ൌ 4 (i.e., ^^ୟ ୗ ୮ୖୗ ൌ 8 and ^^^ୈ^ ൌ 2), the number of SRS symbols is ^^^ ୗ ^ୖ ୫ୗ ୠ ൌ 8, the repetition factor is ^^ ൌ 4, and intra-slot frequency hopping is not configured. FIG.20 shows SRS TDM combined with SRS repetition. Here, p0, p1, …, p7 are the SRS ports. In some embodiments, when TDM and frequency hopping are both configured, the same frequency hopping counter is used to determine the frequency-domain position for all subsets of SRS ports. In some embodiments, when both TDM and frequency hopping are configured, for ap-SRS, all SRS ports within a subset of SRS ports may be sounded within a slot in which SRS is transmitted. FIG.21 shows an example of SRS TDM according to the above embodiments for the case when the number of SRS ports per subset of SRS symbols is ^^ୟ ୗ ୮ୖୗ⁄ ^^^ୈ^ ൌ 4 (i.e., ^^ୟ ୗ ୮ୖୗ ൌ 8 and ^^^ୈ^ ൌ 2), the number of SRS symbols is ^^^ ୗ ^ୖ ୫ୗ ୠ ൌ 8, the repetition factor is ^^ ൌ 2, and intra-slot frequency hopping over two hops is configured. FIG.21 shows SRS TDM combined with SRS frequency hopping over two hops (per subset of ports). Here, p0, p1, …, p7 are the SRS ports. FIG.22 is an example of SRS TDM according to the above embodiments for the case when the number of SRS ports per subset of SRS symbols is ^^ୟ ୗ ୮ୖୗ⁄ ^^^ୈ^ ൌ 4 (i.e., ^^ୟ ୗ ୮ୖୗ ൌ 8 and ^^^ୈ^ ൌ 2), the number of SRS symbols is ^^^ ୗ ^ୖ ୫ୗ ୠ ൌ 8, the repetition factor ൌ 1, and intra-slot frequency hopping over four hops is configured. In FIG.22, SRS TDM is combined with SRS frequency hopping over four hops (per subset of ports). Here, p0, p1, …, p7 are the SRS ports. Cyclical mapping A benefit with the above approach (e.g., with the pattern in FIG.22) is that CSI may be acquired for each subset of SRS ports with a minimum time interval between the first and last transmission occasion of a same SRS port, which mitigates channel-aging effects. The drawback with the above approach is that frequency hopping may cause phase discontinuities and, hence, the network node 16 may measure a phase shift between a first and second set of SRS ports without being able to determine whether this phase shift is due to the channel or due to the frequency hopping. In an alternative embodiment, if repetition is configured, and neither frequency hopping nor RPFS are configured, then the orthogonal subsets of ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^ SRS ports will be transmitted in a cyclic manner, e.g., as follows: SRS ports 0, … , ^^ୗୖୗ ୟ୮ ⁄ ^^^ୈ^ െ 1 are transmitted in SRS symbols 0, ^^^ୈ^, 2 ^^^ୈ^, 3 ^^^ୈ^, … ^^^ୈ^ , … , 2 ∙ ^^ୟୗ ୮ୖୗ⁄ ^^^ୈ^ െ 1 are transmitted in SRS symbols 1, ^^^ୈ^ ^ 1, 2 ^^^ୈ^ ^ 1, 3 ^^^ୈ^ ^ 1, … SRS ports 2 ∙ ^^ୗୖୗ ୟ୮ ⁄ ^^^ୈ^ , … , 3 ∙ ^^ୗୖୗ ୟ୮ ⁄ ^^^ୈ^ െ 1 are transmitted in SRS symbols 2, ^^^ୈ^ ^ 2, 2 ^^^ୈ^ ^ 2, 3 ^^^ୈ^ ^ 2, … Etc. The ^^^୦ ^ ^^ ൌ 1,2, … , ^^^ୈ^^ orthogonal set of SRS ports: ே^^ ౦^^ ே^^ ౦^^ ே^^^ ^ ^^ െ 1^ ∙ி^ీ^ , ^ ^^ െ 1^ ∙ி^ీ^ ^ 1, … , ^^ ∙ ^౦ ி^ీ^ െ 1, are ^ ^^ െ 1^, 1 ∙ ^^^ୈ^ ^ ^ ^^ െ 1^, 2 ∙ ^^^ୈ^ ^ ^ ^^ െ 1^, 3 ∙ ^^்^ெ ^ ^ ^^ െ 1^, …. In some embodiments, all ^^ୟ ୗ ୮ୖୗ SRS ports are transmitted in the first ^^^ୈ^ symbols, the 2nd repetition of all ^^ୟ ୗ ୮ୖୗ SRS ports are transmitted in the next ^^^ୈ^ symbols, etc. If the SRS transmitted by the WD 22 is being sounded by a first transmission-reception point (TRP) that has a good coverage to the WD 22, then the first TRP may just measure all ^^ୟ ୗ ୮ୖୗ SRS ports in the first ^^^ୈ^ symbols with sufficient quality and does not need to measure the remaining repetitions. On the other hand, if the SRS transmitted by the WD 22 is being sounded by a second TRP that has a poor coverage with respect to the WD 22, then the second TRP may measure multiple repetitions of all ^^ୟ ୗ ୮ୖୗ SRS ports to improve the estimated channel quality on the SRS. FIG.23 shows an example of SRS TDM according to the above alternative embodiment for the case when the number of SRS ports per subset of SRS symbols is ^^ୗୖୗ⁄ ^^ ൌ 4 (i.e., ^^ୗୖୗ ൌ 8 and ^^ ൌ 2), the number of S ୗୖୗ ୟ୮ ^ୈ^ ୟ୮ ^ୈ^ RS symbols is ^^^^୫ୠ ൌ frequency hopping is not configured. In FIG.23, SRS TDM is combined with SRS repetition for an alternative embodiment. Here, p0, p1, …, p7 are the SRS ports. In some embodiments, when both TDM and frequency hopping (or RPFS) is configured, all SRS ports may be sounded before the frequency is hopped. This strategy is illustrated in FIG.24 for the same configuration as the pattern in FIG.21. FIG.24 shows SRS TDM combined with SRS frequency hopping over two hops (per subset of ports) and with alternative mapping. Here, p0, p1, …, p7 are the SRS ports. RRC configuration of the mapping pattern (sequential or cyclic mapping) In some embodiments, the time-domain mapping pattern (i.e., sequential or cyclic mapping) may be RRC configured per SRS resource, for example as per the following (in ASN): SRS-Resource ::= SEQUENCE { srs-ResourceId SRS-ResourceId, nrofSRS-Ports ENUMERATED {port1, ports2, ports4, ports8}, ... [[ ... timeDivisionDuplexing-r18 SEQUENCE { mappingPattern-r18 ENUMERATED {sequentialMapping, cyclicMapping} } OPTIONAL, -- Cond 8Tx } ... ]] Other aspects In some embodiments, if RRC configured values of ^^^ ୗ ^ୖ ୫ୗ ୠ and ^^^ୈ^ are such that ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ is not an integer, only ^^^ୈ^^ ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ ^ symbols will contain SRS (e.g., the last ^^^ ୗ ^ୖ ୫ୗ ୠ െ ^^^ୈ^^ ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ ^ does not contain SRS). As before, subsets of SRS ports subsets of the occupied ^^ ^ ^^ୗୖୗ / ^^ symbols. ^ୈ^ ^^୫ୠ ^ୈ^ ^ In some embodiments, if RRC configured values of ^^^ ୗ ^ୖ ୫ୗ ୠ and ^^^ୈ^ are such that ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ is not an integer, the number of symbols per subset of SRS ports may vary ports. In some embodiments, if RRC configured values of ^^^ ୗ ^ୖ ୫ୗ ୠ and ^^^ୈ^ are such that ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ is not an integer, the number of symbols and the number of SRS ports per subset of SRS ports may vary over the subsets of SRS ports. Alternate embodiments In some embodiments, an SRS resource configured with TDM factor ^^^ୈ^ and ^^^ ୗ ^ୖ ୫ୗ ୠ symbols will span a total ^^^ୈ^ ^^^ ୗ ^ୖ ୫ୗ ୠ symbols. In other words, the legacy (in existing NR specification) parameter ^^^ ୗ ^ୖ ୫ୗ ୠ is reinterpreted as the number of OFDM symbols per subset of SRS ports. In some embodiments, the starting symbol position for the ^^th subset of SRS ports, ^^ ൌ 0,1, … , ^^^ୈ^ െ 1, is ^^^ ^ ^^ ^^^ ୗ ^ୖ ୫ୗ ୠ , where ^^^ is the RRC-configured starting position for the SRS resource. In some embodiments, the starting position may be explicitly configured, in RRC, for each subset of SRS ports. Mapping of subset of SRS ports to comb offsets and CSs How to allocate comb offsets and CSs for each of the subset of SRS ports is considered next. In some embodiments, when an SRS resource is configured with TDM, the comb offset and cyclic shifts are configured using legacy RRC fields. Specifically, the higher- layer parameter transmissionComb for transmission comb 2 and 4, and transmissionComb-n8-r17 for transmission comb 8. To support this behavior, legacy SRS port-to-CS and SRS port-to-comb-offset formulas need to be modified, e.g., as per the following. In some embodiments, the same set of comb offsets and CSs are used for an 8-port SRS resource without regard to whether TDM is configured. This implies that the set of comb offsets and CSs are different for different subsets of SRS ports. In some embodiments, the same set of comb offset and CSs are occupied by each subset of SRS ports, which simplifies co-scheduling of other SRS resources in a same set of time/frequency resources. In the following, some example embodiments are considered, assuming that the first subset of SRS ports are 0, … , ^^ୟ ୗ ୮ୖୗ⁄ ^^^ୈ^ െ 1, the second subset of SRS ports are ^^ୟ ୗ ୮ୖୗ⁄ ^^^ୈ^ , … , 2 ∙ ^^ୟ ୗ ୮ୖୗ⁄ ^^^ୈ^ െ 1, and so on. 2, SRS ports ^^ ∈ ^ ^1000, 1001, 1002, 1003^ are in a first subset and ^^^ ∈ ^1004, 1005, 1006, 1007^ The CS ^^^ for antenna port ^^^ is given by cs,^ ^^^ ൌ 2 ^^ ^^ cs S ,R mS ax. Here, ^^୫ୟ^ is the maximum cs,^ shifts per comb offset and ^^SRS given by: ^ SRS ì ^^ cs,max S ^^ ^^^mod ^ ^ap ^ െ 1000^ൗ 2 ^ ïæ RS ^^^ୈ^ ö Here, ^^S cs RS is the RRC-configured cyclic shift (contained in the higher-later parameter transmissionComb). Note that ^^େ ୫ ୗୟ^ ൌ 6 is equivalent to transmission comb 8 being configured. Note that if TDM is not configured, then ^^^ୈ^ ൌ 1 according to a previous embodiment and the above formula reduces to a legacy port-to-CS formula. The comb offset ^^^^^^ TC for antenna port ^^^ is given by: SRS ì ൬ ^ത ^^ ^TC ^ TC ^ ^^ mod if ap ^ ^^SRS ൌ 4, ^^ mod ap ^ ^ 1000 ∈ ^1001, 1003^, and ^^cs,max ൌ 6 ï 2 ^^ ^ SRS ^ୈ^ ^^^ୈ^ parameter transmissionComb) and ൌ , … , ^^ െ 1 to a embodiment and the above formula reduces to a legacy port-to-comb-offset formula. Extensions Cyclic-shift and/or comb-offset hopping will be supported for SRS in NR 3GPP Rel-18, which requires updated formulas for mapping SRS ports to comb offsets and cyclic shifts. Hopping patterns and formulas for mapping SRS ports to comb offsets and cyclic shifts may be provided. In some embodiments, when an 8-port SRS resource is configured with both TDM and cyclic-shift and/or comb-offset hopping, the hopping pattern and formulas, for each subset of ^^ SRS ports, may be the same as the hopping pattern for a ^^-port SRS resource. Some embodiments may include one or more of the following: Embodiment A1. A network node configured to communicate with a wireless device (WD), the network node configured to, and/or comprising a radio interface and/or comprising processing circuitry configured to: associate a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols, the associating being according to one of a sequential mapping pattern and a cyclical mapping pattern. Embodiment A2. The network node of Embodiment A1, wherein SRS ports in the subset of SRS ports are mapped to comb offsets and cyclic shifts according to a mapping rule. Embodiment A3. The network node of Embodiment A2, wherein a same set of comb offsets and cyclic shifts are used for all subsets of a plurality of SRS port subsets. Embodiment A4. The network node of Embodiment A3, wherein a same set of comb offsets and cyclic shifts over all of subsets of the plurality of SRS port subsets are used for an SRS resource not configured with time division duplexing, TDM. Embodiment A5. The network node of any of Embodiments A1-A4, wherein the one of the sequential mapping pattern and the cyclical mapping pattern is radio resource control, RRC, configured for each SRS resource of a plurality of SRS resources. Embodiment A6. The network node of any of Embodiments A1-A5, wherein, when both time division multiplexing, TDM, and frequency hopping are configured, a plurality of SRS ports of the subset of SRS ports are sounded before frequency hopping. Embodiment A7. The network node of Embodiment A6, wherein all SRS ports of the subset of SRS ports are sounded within a slot of SRS transmission. Embodiment A8. The network node of any of Embodiments A1-A7, wherein, when both time division multiplexing, TDM, and frequency hopping are configured, a same frequency hopping counter is used to determine a frequency domain position for all subsets of SRS ports. Embodiment B1. A method implemented in a network node, the method comprising: associating a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols, the associating being according to one of a sequential mapping pattern and a cyclical mapping pattern. Embodiment B2. The method of Embodiment B1, wherein SRS ports in the subset of SRS ports are mapped to comb offsets and cyclic shifts according to a mapping rule. Embodiment B3. The method of Embodiment B2, wherein a same set of comb offsets and cyclic shifts are used for all subsets of a plurality of SRS port subsets. Embodiment B4. The method of Embodiment B3, wherein a same set of comb offsets and cyclic shifts over all of subsets of the plurality of SRS port subsets are used for an SRS resource not configured with time division duplexing, TDM. Embodiment B5. The method of any of Embodiments B1-B4, wherein the one of the sequential mapping pattern and the cyclical mapping pattern is radio resource control, RRC, configured for each SRS resource of a plurality of SRS resources. Embodiment B6. The method of any of Embodiments B1-B5, wherein, when both time division multiplexing, TDM, and frequency hopping are configured, a plurality of SRS ports of the subset of SRS ports are sounded before frequency hopping. Embodiment B7. The method of Embodiment B6, wherein all SRS ports of the subset of SRS ports are sounded within a slot of SRS transmission. Embodiment B8. The method of any of Embodiments B1-B7, wherein, when both time division multiplexing, TDM, and frequency hopping are configured, a same frequency hopping counter is used to determine a frequency domain position for all subsets of SRS ports. Embodiment C1. A wireless device configured to communicate with an network node, the WD configured to, and/or comprising a radio interface and/or comprising processing circuitry configured to: receive a configuration of a one of a sequential mapping pattern and a cyclical mapping pattern for associating a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols; and determine the subset of SRS symbols based at least in part on the received mapping configuration. Embodiment C2. The WD of Embodiment C1, wherein the configuration is received on radio resource control, RRC, signaling. Embodiment D1. A method in a wireless device configured to communicate with an network node, the method comprising: receiving a configuration of a one of a sequential mapping pattern and a cyclical mapping pattern for associating a subset of sounding reference signal, SRS, ports with a subset of configured SRS symbols; and determining the subset of SRS symbols based at least in part on the received mapping configuration. Embodiment D2. The method of Embodiment D1, wherein the configuration is received on radio resource control, RRC, signaling. As will be appreciated by one of skill in the art, the concepts described herein may be embodied as a method, data processing system, computer program product and/or computer storage media storing an executable computer program. Accordingly, the concepts described herein may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or “module.” Any process, step, action and/or functionality described herein may be performed by, and/or associated to, a corresponding module, which may be implemented in software and/or firmware and/or hardware. Furthermore, the disclosure may take the form of a computer program product on a tangible computer usable storage medium having computer program code embodied in the medium that may be executed by a computer. Any suitable tangible computer readable medium may be utilized including hard disks, CD-ROMs, electronic storage devices, optical storage devices, or magnetic storage devices. Some embodiments are described herein with reference to flowchart illustrations and/or block diagrams of methods, systems and computer program products. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, may be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer (to thereby create a special purpose computer), special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer program instructions may also be stored in a computer readable memory or storage medium that may direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. It is to be understood that the functions/acts noted in the blocks may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows. Computer program code for carrying out operations of the concepts described herein may be written in an object oriented programming language such as Python, Java® or C++. However, the computer program code for carrying out operations of the disclosure may also be written in conventional procedural programming languages, such as the "C" programming language. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer. In the latter scenario, the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments may be combined in any way and/or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination. Abbreviations that may be used in the preceding description include: Abbreviation Explanation 3GPP Third Generation Partnership Project ap-SRS Aperiodic SRS ASN Abstract Syntax Notation BPSK Binary Phase Shift Keying BWP Bandwidth Part CA Carrier Aggregation CB Codebook CDM Code Division Multiplexing CE Control Element CP-OFDM Cyclic Prefix OFDM CRB Carrier RB CG Configured Grant CS Cyclic Shift CS-RNTI Configured Scheduling RNTI CSI Channel State Information DCI Downlink Control Information DFT Discrete Fourier Transform DFT-S-OFDM DFT Spread OFDM DG Dynamic Grant DL Downlink DMRS Demodulation RS FD-OCC Frequency Domain OCC FDD Frequency-Division Multiplexing FR1 Frequency Range 1 FR2 Frequency Range 2 IDFT Inverse DFT gNB gNodeB IE Information Element LSB Least Significant Bit LTE Long Term Evolution MAC Medium Access Control MCS Modulation and Coding Scheme MIB Master Information Block MIMO Multiple-Input Multiple-Output MSB Most Significant Bit NCB Non-Codebook NDI New Data Indicator NR New Radio NW Network OCC Orthogonal Cover Code OFDM Orthogonal Frequency Division Multiplexing p-SRS Periodic SRS PA Power Amplifier PAPR Peak-to-Average Power Ratio PC Power Control PCell Primary Cell PDCCH Physical Downlink Control Channel PDSCH Physical Downlink Shared Channel PRB Physical RB PSD Power Spectral Density PTRS Phase Tracking Reference Signal PUCCH Physical Uplink Control Channel PUSCH Physical Uplink Shared Channel QPSK Quadrature Phase-Shift Keying RB Resource Block RBG Resource Block Group RE Resource Element RF Radio Frequency RPFS RB-level Partial Frequency Sounding RS Reference Signal RSRP RS Received Power RIV Resource Indication Value RNTI Radio Network Temporary Identifier RRC Radio Resource Control RV Redundancy Version Rx Receive SCS Subcarrier Spacing SCell Secondary Cell SIB1 System Information Block 1 SLIV Start and Length Indicator Value sp-SRS Semi-Persistent SRS SNR Signal-to-Noise Ratio SRI SRS Resource Indicator SRS Sounding Reference Signal SRSI SRS Resource Set Indicator SSB Synchronization Signal Block SUL Supplementary Uplink TB Transport Block TD-OCC Time Domain OCC TDD Time-Division Duplexing TDM Time-Division Multiplexing Tx Transmit UE User Equipment UL Uplink VRB Virtual RB It will be appreciated by persons skilled in the art that the embodiments described herein are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.

Claims

What is claimed is: 1. A method in a network node (16) configured to communicate with a wireless device, WD (22), the method comprising: configuring (S140) the WD (22) with cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped; and configuring (S142) the WD (22) to perform SRS transmissions according to the cyclical mapping.
2. The method of Claim 1, wherein a number of SRS ports in a subset of SRS ports of the N subsets is a ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^, the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ^^ୟ ୗ ୮ୖୗ denotes a number of SRS ports per SRS resource and ^^^ୈ^ is a TDM factor equal to N.
3. The method of Claim 2, wherein ^^^ୈ^ is equal to 2 when TDM is configured and ^^^ୈ^ is equal to 1, otherwise.
4. The method of any of Claims 2 and 3, wherein only combinations of ^^^ ୗ ^ୖ ୫ୗ ୠ and ^^^ୈ^ that result in a ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, being an integer are configured, where ^^^ ୗ ^ୖ ୫ୗ ୠ is equal to M and is radio resource control, RRC, configured .
5. The method of Claim 4, wherein the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, being greater than 1 is allowed only when an SRS resource is configured with one or more of repetition, frequency hopping and RPFS.
6. The method of Claim 4, wherein, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then the nearest integer less than the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ is a number of SRS symbols per subset of SRS ports.
7. The method of Claim 4, wherein, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then a number of symbols per subset of SRS ports varies over the N subsets of SRS ports.
8. The method of Claim 4, wherein, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then a number of symbols and a number of SRS ports per subset of SRS ports varies over the N subset of ports.
9. The method of any of Claims 4-8, wherein, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is greater than 1 and repetition, frequency hopping and RPFS are not configured, then ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^ SRS ports per subset of SRS symbols are repeated over ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ OFDM symbols.
10. The method of any of Claims 2-9, further comprising configuring the WD (22) to transmit a repetition of ^^ୟ ୗ ୮ୖୗ SRS ports in each of a plurality of successive sets of ^^^ୈ^ symbols.
11. The method of any of Claims 2-10, further comprising configuring the WD (22) to sound SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured.
12. The method of any of Claims 2-11, wherein a same set of comb offsets and cyclic shifts, CS, are occupied by each subset of SRS ports.
13. The method of any of Claims 2-11, wherein a comb offset for an antenna port is based at least in part on the ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^.
14. The method of any of Claims 2-13, wherein a cyclic shift for an antenna port is based at least in part on the ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^.
15. The method of any of Claims 2-14, wherein, when an 8 port SRS resource is configured with both TDM and cyclic-shift hopping or with both TDM and comb-offset hopping, then a hopping pattern for each subset of an number ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^ of SRS ports is a same hopping pattern for a ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^ port SRS resource.
16. A method in a wireless device, WD (22), configured to communicate with a network node (16), the method comprising: receiving (S144) from the network node (16) cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped; cyclically mapping (S146) the N subsets of SRS ports to the M OFDM symbols; and performing (S148) SRS transmissions according to the cyclical mapping.
17. The method of Claim 16, wherein a number of SRS ports in a subset of SRS ports of the N subsets is a ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^, the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ^^ୟ ୗ ୮ୖୗ denotes a number of SRS ports per SRS resource and ^^^ୈ^ is a TDM factor equal to N.
18. The method of Claim 17, further comprising transmitting a repetition of ^^ୟ ୗ ୮ୖୗ SRS ports in each of a plurality of successive sets of ^^^ୈ^ symbols.
19. The method of any of Claims 17 and 18, further comprising sounding SRS ports in a subset of SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured.
20. The method of any of Claims 16-19, wherein, when time division multiplexing and frequency hopping are both configured, using a same frequency counter to determine a frequency domain position for all subsets of SRS ports.
21. A network node (16) configured to communicate with a wireless device, WD (22), the network node (16) configured to: configure the WD (22) with cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped; and configure the WD (22) to perform SRS transmissions according to the cyclical mapping.
22. The network node (16) of Claim 21, wherein a number of SRS ports in a subset of SRS ports of the N subsets is a ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^, the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ^^ୟ ୗ ୮ୖୗ denotes a number of SRS ports per SRS resource and ^^^ୈ^ is a TDM factor equal to N.
23. The network node (16) of Claim 22, wherein ^^^ୈ^ is equal to 2 when TDM is configured and ^^^ୈ^ is equal to 1, otherwise.
24. The network node (16) of any of Claims 22 and 23, wherein only combinations of ^^^ ୗ ^ୖ ୫ୗ ୠ and ^^^ୈ^ that result in a ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, being an integer are configured, where ^^^ ୗ ^ୖ ୫ୗ ୠ is equal to M and is radio resource control, RRC, configured.
25. The network node (16) of Claim 24, wherein the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, being greater than 1 is allowed only when an SRS resource is configured with one or more of repetition, frequency hopping and RPFS.
26. The network node (16) of Claim 24, wherein, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then the nearest integer less than the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^ is a number of symbols per subset of SRS ports.
27. The network node (16) of Claim 24, wherein, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then a number of symbols per subset of SRS ports varies over the N subsets of SRS ports.
28. The network node (16) of Claim 24, wherein, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is not an integer, then a number of symbols and a number of SRS ports per subset of SRS ports varies over the N subset of ports.
29. The network node (16) of any of Claims 24-27, wherein, when the ratio, ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, is greater than 1 and repetition, frequency hopping and RPFS are not configured, then ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^ SRS ports per subset of SRS symbols are repeated over ^^^ ୗ ^ୖ ୫ୗ ୠ / ^^^ୈ^, OFDM symbols.
30. The network node (16) of any of Claims 22-29, wherein the network node (16) is configured to configure the WD (22) to transmit a repetition of ^^ୟ ୗ ୮ୖୗ SRS ports in each of a plurality of successive sets of ^^^ୈ^ symbols.
31. The network node (16) of any of Claims 22-30, wherein the network node (16) is configured to configure the WD (22) to sound SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured.
32. The network node (16) of any of Claims 22-31, wherein a same set of comb offsets and cyclic shifts, CS, are occupied by each subset of SRS ports.
33. The network node (16) of any of Claims 22-32, wherein a comb offset for an antenna port is based at least in part on the ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^.
34. The network node (16) of any of Claims 22-33, wherein a cyclic shift for an antenna port is based at least in part on the ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^.
35. The network node (16) of any of Claims 22-34, wherein, when an 8 port SRS resource is configured with both TDM and cyclic shifts or both TDM and comb- offset hopping, then a hopping pattern for each subset of an number P of SRS ports is a same hopping pattern for a P port SRS resource.
36. A wireless device, WD (22), configured to communicate with a network node (16), the WD (22) configured to: receive from the network node (16) cyclical mapping parameters for cyclically mapping sounding reference signal, SRS, ports to SRS symbols, the cyclical mapping parameters including a number, N, of subsets of SRS ports and a number M of orthogonal frequency division multiplexed, OFDM, symbols to which the subsets of SRS ports are cyclically mapped; cyclically map the N subsets of SRS ports to the M OFDM symbols; and perform SRS transmissions according to the cyclical mapping.
37. The WD (22) of Claim 36, wherein a number of SRS ports in a subset of SRS ports of the N subsets is based on a ratio, ^^ୟ ୗ ୮ୖୗ/ ^^^ୈ^, the ratio denoting a number of SRS ports per subset of SRS symbols when time division duplexing, TDM, is configured, where ^^ୟ ୗ ୮ୖୗ denotes a number of SRS ports per SRS resource and ^^^ୈ^ is a TDM factor equal to N.
38. The WD (22) of Claim 37, wherein the WD (22) is configured to transmit a repetition of ^^ୟ ୗ ୮ୖୗ SRS ports in each of a plurality of successive sets of ^^^ୈ^ symbols.
39. The WD (22) of any of Claims 37 and 38, wherein the WD (22) is configured to sound SRS ports in a subset of SRS ports when both TDM and frequency hopping or both TDM and resource block, RB, based partial frequency sounding, RPFS, are configured.
40. The WD (22) of any of Claims 36-39, wherein, when time division multiplexing and frequency hopping are both configured, using a same frequency counter to determine a frequency domain position for all subsets of SRS ports.
EP24706094.0A 2023-02-17 2024-02-16 Time division multiplexing (tdm) for 8-port sounding reference signals (srs) Pending EP4666503A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US202363485786P 2023-02-17 2023-02-17
PCT/EP2024/054079 WO2024170780A1 (en) 2023-02-17 2024-02-16 Time division multiplexing (tdm) for 8-port sounding reference signals (srs)

Publications (1)

Publication Number Publication Date
EP4666503A1 true EP4666503A1 (en) 2025-12-24

Family

ID=89983114

Family Applications (1)

Application Number Title Priority Date Filing Date
EP24706094.0A Pending EP4666503A1 (en) 2023-02-17 2024-02-16 Time division multiplexing (tdm) for 8-port sounding reference signals (srs)

Country Status (3)

Country Link
EP (1) EP4666503A1 (en)
CN (1) CN120937291A (en)
WO (1) WO2024170780A1 (en)

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021155586A1 (en) * 2020-02-07 2021-08-12 Qualcomm Incorporated Sounding reference signal (srs) enhancements
EP4309326A2 (en) * 2021-04-05 2024-01-24 Huawei Technologies Co., Ltd. Methods and apparatus for srs transmission and signaling
WO2023196693A2 (en) * 2022-08-11 2023-10-12 Futurewei Technologies, Inc. Methods and apparatus for enhancement of srs

Also Published As

Publication number Publication date
WO2024170780A1 (en) 2024-08-22
CN120937291A (en) 2025-11-11

Similar Documents

Publication Publication Date Title
US12114304B2 (en) Medium access control (MAC) control element signaling for multi-transmission point/multi panel physical downlink shared channel transmission
US12426043B2 (en) Rate matching for non-coherent joint-transmission with dynamic spectrum sharing
US11711250B2 (en) Multi-numerology frame structure for NR operation in mm-wave frequency bands
US11902194B2 (en) Channel state information reference signal resource mapping
AU2017338040A1 (en) Control of aperiodic signalling of SRS for wireless systems
US20220337365A1 (en) Flexible reconfiguration of the sounding reference signal
EP4690521A1 (en) Unified channel state information (csi) framework for spatial and power domain adaptation for network energy saving
US20230179347A1 (en) Signaling support for enhanced frequency hopping for ap srs
US20250192860A1 (en) Explicit Common Beam Index Configuration for Physical Uplink Control Channel (PUCCH)
WO2024079319A1 (en) Rank restriction for multi-panel ul transmission
EP4052403B1 (en) Sharing of sounding reference signals (srs) resources between new radio and long term evolution
WO2024170780A1 (en) Time division multiplexing (tdm) for 8-port sounding reference signals (srs)
US20250080186A1 (en) Framework and signaling for non-coherent joint transmission (ncjt) channel state information (csi) selection
EP4612829A1 (en) Signalling of an identifier to indicate at least 5 uplink dmrs ports
WO2024095214A1 (en) Antenna port tables for physical downlink shared channel (pdsch) for up to 8 layers
WO2025036853A1 (en) Multi-layer discrete fourier transform spread orthogonal frequency division multiplexing (dft-s-ofdm) for single downlink control information (dci) simultaneous transmission from multiple panels (stxmp)
WO2026075608A1 (en) Srs configurations and procedures for subband full duplex operation
WO2024079191A1 (en) Dmrs decoding co-scheduling assumptions
OA20658A (en) Flexible reconfiguration of the sounding reference signal.

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20250917

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC ME MK MT NL NO PL PT RO RS SE SI SK SM TR