WO2017180052A1 - Procédé et appareils de génération de signal de référence - Google Patents

Procédé et appareils de génération de signal de référence Download PDF

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Publication number
WO2017180052A1
WO2017180052A1 PCT/SE2017/050370 SE2017050370W WO2017180052A1 WO 2017180052 A1 WO2017180052 A1 WO 2017180052A1 SE 2017050370 W SE2017050370 W SE 2017050370W WO 2017180052 A1 WO2017180052 A1 WO 2017180052A1
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Prior art keywords
sequence
length
reference signal
concatenating
elements
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PCT/SE2017/050370
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English (en)
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Ricardo BLASCO SERRANO
Stefano Sorrentino
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Telefonaktiebolaget Lm Ericsson (Publ)
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/0224—Channel estimation using sounding signals
    • H04L25/0226—Channel estimation using sounding signals sounding signals per se
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J13/00—Code division multiplex systems
    • H04J13/10—Code generation
    • H04J13/102—Combining codes
    • H04J13/107—Combining codes by concatenation
    • 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
    • H04L27/2647—Arrangements specific to the receiver only
    • 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
    • H04L5/0016—Time-frequency-code
    • 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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J13/00—Code division multiplex systems
    • H04J13/0007—Code type
    • H04J13/0022—PN, e.g. Kronecker
    • H04J13/0029—Gold

Definitions

  • the present disclosure relates to the generation and transmission of reference signals used for channel estimation for radio communication and in particular for sidelink or Device-to- Device (D2D) communication and in particular to methods and an apparatuses for transmitting and/or receiving reference signals wherein the sequences of reference signals reduce correlation and interference between radio links, in particular between sidelinks.
  • D2D Device-to- Device
  • Rel-12 The Third Generation Partnership Project (3GGP) Release 12 (Rel-12) of the long term evolution (LTE) standard has been extended with support of D2D (also referred to as "sidelink”) features targeting both commercial and public safety applications.
  • 3GGP Third Generation Partnership Project
  • Rel-12 LTE Some applications enabled by Rel-12 LTE are device discovery, where devices are able to sense the proximity of another device and associated application by broadcasting and detecting discovery messages that carry device and application identities.
  • Another application consists of direct communication based on physical channels terminated directly between devices.
  • One of the potential extensions for the D2D systems includes support for V2x
  • V2x communication which includes any combination of direct communication between vehicles Vehical-to-Vehicle (V2V), Vehicle-to-Infrastructure (V2I) communication, or Vehicle-to- Pedestrians (V2P).
  • V2x communication may take advantage of a NetWork (NW) infrastructure, when available, but at least basic V2x connectivity should be possible even in case of lack of coverage.
  • NW NetWork
  • Providing an LTE -based V2x interface may be economically advantageous because of the LTE economies of scale and it may enable tighter integration between communications with the NW Infrastructure (V2I) and V2P and V2V
  • V2x communications may carry both non-safety and safety information, where each of the applications and services may be associated with specific requirements sets, e.g., in terms of latency, reliability, capacity, etc.
  • European Telecommunication Standards Institute ETSI
  • CAM Co-operative Awareness Message
  • DENM Decentralized Environmental Notification Message
  • the CAM message is intended to enable vehicles, including emergency vehicles, to notify their presence and other relevant parameters in a broadcast fashion. Such messages target other vehicles, pedestrians, and infrastructure, and are handled by their applications.
  • CAM messages also serve as active assistance to safety driving for normal traffic.
  • the package size of CAM and DENM message varies from 100+ to 800+ bytes and the typical size is around 300 bytes. The message is supposed to be detected by all vehicles in proximity.
  • SAE Society of the Automotive Engineers
  • BSM Basic Safety Message
  • DSRC Dedicated Short-Range Communications
  • DMRS DeModulation Reference Signals
  • OFDM Orthogonal Frequency Division Multiplexing
  • Figure 2 shows a 1 ms long subframe including 14 OFDM symbols, a 1 OFDM symbol being the Guard Period (GP) including 6 subcarriers spanning the mapped reference symbols and also showing a so-called Automatic Gain Control (AGC) settling.
  • AGC circuits are usually employed in many systems where the amplitude of an incoming signal may vary over a wide dynamic range. The role of a AGC circuit is to provide a relatively constant output amplitude so that circuits following the AGC circuit require less dynamic range. If the variation in signal level is much slower than the information rate contained in the signal, then an AGC circuit can be used to provide a signal with a well-defined average level to downstream circuits.
  • GP Guard Period
  • AGC Automatic Gain Control
  • the time to adjust the gain in response to an input amplitude change should remain constant, independent of the input amplitude level and hence gain setting of the amplifier. Achieving a constant gain settling time permits the AGC loop's bandwidth to be maximized for fast signal acquisition while maintaining stability over all operating conditions.
  • the radio communication channel is correlated in time. That is, channel samples taken sufficiently close to each other are similar (in a statistical sense).
  • the properties of time correlation depend on the carrier frequency and the speed of the mobile terminals or User Equipments (UEs) as well as other aspects such as the propagation environment, etc. This correlation is usually exploited by the channel estimation algorithms for example by applying some time-domain filtering.
  • a receiver may receive a linear combination of the reference signals sent by multiple transmitters. Most often, the receiver is interested in estimating the channel from each individual transmitter (rather than the combined channel from all the transmitters). For that purpose the receiver may make use of the time correlation properties of the channel.
  • One common way to do this is to ensure that the sequences of reference symbols transmitted by the interfering UEs have good cross correlation properties.
  • LTE uses Orthogonal Cover Codes (OCCs) to generate orthogonal sequences and semi -orthogonal base sequences. With semi- orthogonal we refer to sequences with low cross correlation properties.
  • LTE specifies the following OCC [1,1], [1,-1] .
  • Such codes may determine a phase shift between DMRS's transmitted in different symbols. Since the codes are mutually orthogonal, DMRS transmissions that use different codes and that affect highly correlated radio channels may in principle be canceled from each other thanks to the code properties. On the other hand, transmissions with same OCC interfere maximally with each other.
  • sidelink and especially for V2V applications in general radio communication using higher carrier frequencies (e.g. up to and above 6 GHz), we observe the following limitations: lack of a central control node in certain scenarios (e.g., out of eNB coverage) complicates the possibility of coordinating OCC values in order to orthogonalize transmissions with strong potential mutual interference. The occurrence of worst- case scenarios where interfering UEs use the same OCC is thus higher than in cellular communication.
  • the receiver may miss detection of some DMRS symbols and lose orthogonality between DMRS with different OCC.
  • a method for operating a User Equipment comprises transmitting (40) a reference signal, the reference signal being based on a first sequence, S 1 and/or a second sequence, S2.
  • a method for operating a User Equipment, US comprises receiving (50) a reference signal, the reference signal being based on a first sequence, S I of length Ns.
  • a wireless device 12, or User Equipment, US is disclosed.
  • the User Equipment, UE is suitable for use in a radio communications system.
  • the user equipment UE comprises a processing circuit and a memory, said memory containing instructions executable by said processing circuitry whereby said UE is operative to obtain a first sequence, S 1 and to transmit a reference signal based on the first sequence, S I.
  • a wireless device, 12, or A User Equipment, UE is disclosed.
  • the User Equipment, UE is suitable for use in a radio communications system, the user equipment comprising a processing circuit and a memory, said memory containing instructions executable by said processing circuitry whereby said UE is operative to obtain a first sequence, S I and receive a reference signal based on the first sequence, S I.
  • a transformation such as e.g. apply a cyclic shift
  • the proposed embodiments solve the aforementioned problems by replacing the OCC with a different family of codes and/or sequences.
  • the codes enjoy different properties than OCC, such as e.g. they do not aim at orthogonality between UEs but rather at low cross correlation across or between a large number of codes and/or sequences.
  • family of codes is robust when correlating truncated versions of the codes and/or sequences (a property that is beneficial in case of symbols dropping for e.g. AGC training or in case of short time correlation of the channel).
  • the invention proposes different ways of generating such codes and/or sequences in a UE- specific way by use of cyclic shifts in the code domain.
  • FIG. 1 is a block diagram of a wireless network or system supporting D2D or sidelink communications, wherein the network shows V2x scenarios for an LTE based network e.g. 4G or 5G utilizing principles of the present disclosure;
  • FIG. 2 shows mapping of reference symbols to every OFDM symbol with fixed subcarriers.
  • FIG. 3 shows mapping of reference symbols to every OFDM symbol with varying subcarriers;
  • FIG. 4 is a block diagram of a method performed by a UE in accordance with principles of the present disclosure.
  • FIG. 5 is a block diagram of an exemplary embodiment of a UE constructed in accordance with principles of the present disclosure.
  • the present disclosure relates to the generation, mapping, and transmission of reference signals used for channel estimation for sidelink or Device-to-Device (D2D) communication and in particular to methods and apparatuses for the purpose of generating sequences of reference signals and the mapping of them to subframes using implicit or explicit rules that reduce cross correlation and interference across D2D or sidelink capable UEs.
  • the method and arrangements disclosed herein may be used for cellular or direct communication in general.
  • the present disclosure is in the context of D2D (or sidelink, peer to peer, or ProSe, proximity services) and particularly V2V or V2x systems wherein the channel conditions may vary rapidly.
  • D2D or sidelink, peer to peer, or ProSe, proximity services
  • V2V or V2x systems wherein the channel conditions may vary rapidly.
  • some of the embodiments herein are applicable for communication among any type of network entities, including uplink from some devices to a central control node.
  • D2D communications are currently under study/standardization as a technology enabler for V2V or V2x communication systems.
  • Acquiring accurate timing and frequency synchronization is critical in D2D communications since the traditional sources of synchronization, e.g., a network (NW) entity such as a base station or an LTE enhanced node B (eNB) are sometimes not involved in the communication (e.g., if the network entities are out of coverage).
  • NW network
  • eNB LTE enhanced node B
  • This is relevant in V2V communications for two reasons: first, wireless devices travel at high speeds resulting in Doppler spread of the signals; and second, the bands dedicated to intelligent transport systems (ITS) are placed at much higher frequencies than those of traditional cellular NWs.
  • ITS intelligent transport systems
  • FIG. 1 illustrates a D2D based V2x or V2V communication network or network, such as an LTE-based network, incorporating the principles of the present disclosure. It should be noted that the present disclosure is not limited to LTE network technologies specifically. The method and arrangement disclosed herein may be applied to other communication network technologies and/or other types of communication on uplink and downlink, such as to the upcoming fifth Generation (5G) technology based network.
  • the D2D communication network 10 includes as previously mentioned several V2x scenarios, including vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P) and vehicle-to-infrastructure (V2I).
  • V2V vehicle-to-vehicle
  • V2P vehicle-to-pedestrian
  • V2I vehicle-to-infrastructure
  • V2V communications allows the driver in one vehicle to warn drivers in other vehicles about roadside hazards and provide forward collision warnings.
  • V2P a vehicle is in communication with pedestrian's wireless device. This allows pedestrians to be informed about threats from car collisions and other roadside hazards.
  • a vehicle communicates with a road side-unit (RSU) via DSRC where the RSU can inform the vehicle's driver with regard to navigation, telematics and other cloud services.
  • RSU road side-unit
  • UE 12 is generally a wireless device.
  • a wireless device is any type of device that is configured or configurable for communication through wireless communication. Examples of such wireless devices are sensors, modems, smart phones, machine type (MTC) devices a.k.a. machine to machine (M2M) devices, PDAs, iPADs, Tablets, smart phones, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, etc.
  • MTC machine type
  • M2M machine to machine
  • PDAs, iPADs, Tablets smart phones, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, etc.
  • LME laptop mounted equipment
  • USB dongles etc.
  • D2D network 10 two or more UEs 12 directly communicate with each other without having the payload traverse the backhaul network.
  • UEs wireless devices 12 in the vicinity of each other can establish a direct radio link, i.e., a D2D bearer. While UEs 12 communicate over the D2D "direct" bearer, they may also maintain a cellular connection with a network entity 20 such as their respective serving base station, for example, an LTE eNB. Network entity 20 serves UEs 12 in a region of coverage of the network entity 20. The UEs 12 may also be out-of-coverage and hence only communicate directly with each other using sidelink or D2D communications.
  • Generating and/or obtaining (41) the sequence S I by performing at least one of the below actions: selecting a base sequence, SO, of length NO with good correlation properties and/or selecting a base sequence SO providing an autocorrelation below a measure and/or threshold
  • a DMRS sequence may be generated by generating a first "base sequence", e.g., from a predefined set of tabulated sequences or according to some predefined algorithm.
  • Such base sequence is typically expected to provide good autocorrelation properties (i.e., the correlation function is nearly an impulse- or Dirac function) and good and/or low cross correlation to other base sequences in order to limit and/or reduce interference.
  • Additional processing can be applied to the base sequence by e.g. applying a so called CS (Cyclic shift) in time domain, or equivalently a phase shift that increases linearly with frequency in the frequency domain.
  • CS Cyclic shift
  • Further processing may consist comprise of applying a time-domain code that spans several symbols (e.g. DMRS symbols and/or OFDM symbols). Additional processing of the sequences is not precluded by this disclosure and it is supported in a non-limiting way. It is observed that both the transmitter and receiver nodes (e.g. wireless devices) need to generate the sequences (e.g. DMRS- and/or code sequences) in order to respectively transmit the DMRS and estimate the channel associated to the received DMRS, which typically involves correlating the received signal with the sequence of the DMRS (e.g. a code sequence). Once the sequence (e.g. DMRS- and/or code sequences) has been generated, it is mapped to a subset of the REs (resource elements) for transmission.
  • Current sidelink specifications assume the following procedure:
  • Base sequence generation A base sequence (e.g a DMRS base sequence) is generated per each OFDM symbol that carries DMRS.
  • Cyclic shift generation and application A CS is applied to each base sequence according to predefined procedures for determining a symbol-specific and in certain cases transmitter-ID-specific CS value.
  • OCC generation and application A OCC (orthogonal cover code) is applied across the symbols (e.g. DMRS symbols and/or OFDM symbols) in time domain, by applying a symbol-specific coefficient (+1/-1) according to one of several predetermined codes (e.g OCC).
  • the code is in certain cases determined based on the ID of the transmitter.
  • DMRS mapping The so determined symbols (e.g. DMRS symbols and/or OFDM symbols) are then transmitted using all the REs corresponding to a UE scheduled bandwidth and over certain predefined symbols (e.g. DMRS symbols and/or OFDM symbols).
  • the invention relates to code sequence generation for DMRS and transmission/reception of the DMRS in relation to step 3 above.
  • a method for operating a a wireless device comprising transmitting (40) a reference signal, the reference signal being based on a first sequence, S 1 and optionally being based on a second sequence, S2.
  • the reference signal may e.g. be a Demodulation Reference Signal, DMRS.
  • the second sequence, S2 may e.g. be a DMRS base sequence as described in 1. above.
  • the first sequence, S I being of length Ns and the reference signal being transmitted in Ns OFDM symbols in a transmission, e.g. during a transmission time interval (e.g. a subframe in LTE).
  • the reference signal being based on a sequence may pertain to the reference signal being generated by modulating a second sequence, S2 with S I.
  • Modulating S2 with S I may comprise multiplying S2 with S I.
  • An example of such a modulation is to multiply e.g the first element in S I with the first the DMRS base sequence in the first OFDM symbol etc. for the rest of the elements in the sequence S I, in the corresponding TTI, to obtain e.g. a phase shift between DMRSs in different OFDM symbols.
  • transmitting a reference signal may comprise mapping of reference symbols to OFDM symbols.
  • a method for operating a wireless device comprising receiving (50) a reference signal, the reference signal being based on a first sequence, S 1 and optionally said reference signal being based on a second sequence, S2.
  • the reference signal may e.g. be a Demodulation Reference Signal, DMRS.
  • the second sequence, S2 may e.g. be a DMRS base sequence as described in 1. above.
  • the first sequence, S I being of length Ns and the reference signal being received in Ns OFDM symbols, e.g. during a corresponding transmission time interval (e.g. a subframe in LTE).
  • S 1 may pertain to the reference signal being generated by modulating a second sequence, S2 with S I.
  • Modulating S2 with S I may comprise multiplying S2 with S I.
  • An example of such a modulation is to multiply e.g the first element in S 1 with the first the DMRS base sequence in the first OFDM symbol in the corresponding TTI to obtain e.g. a phase shift between DMRSs in different OFDM symbols.
  • receiving 50 a reference signal may comprise estimating a channel associated with the received reference signal by correlating the received signal with the first sequence, S 1.
  • the first sequence, S I is generated or obtained by:
  • the first sequence S 1 may be generated or obtained by - applying a cyclic shift to the sequence SO in order to obtain a sequence St of length
  • the first sequence S 1 may correspond to the Orthogonal Cover Code (OCC) obtained in step 3 in the above procedure.
  • OCC Orthogonal Cover Code
  • sequence S 1 may be obtained by reading it from an interface, e.g. reading it from a memory.
  • the second sequence, S2 may have been created by a base sequence generation and a Cyclic shift generation and application as described in relation to 1. and 2. in the procedure above.
  • a base sequence generation in any of the above methods may comprise generating a base sequence (e.g a DMRS base sequence) per each OFDM symbol that comprises DMRS.
  • a Cyclic shift generation and application in this method may comprise applying a Cyclic Shift (CS) to each generated base sequence according to predefined procedures for determining a symbol- specific and in certain cases transmitter-ID-specific CS values.
  • CS Cyclic Shift
  • the first sequence, S I may have been created according to the methods described above to replace 3. in the procedure above to obtain a sequence that is more suitable to handle fast radio channel variations, which may become more explicit when using higher carrier frequencies (up to 6 GHz or even above 6GHz) and in V2V communications when UEs travel at very high speeds (up to 500 km/h relative speed) .
  • the method may comprise generating and/or obtaining (41) the sequence S I, which may be of length Ns.
  • the length, Ns, of S I may correspond to the number of DMRS symbols in a transmission (e.g., in a subframe or TTI).
  • Ns may represent a number of OFDM symbols, within one TTI, which comprises the reference signal or parts of the reference signal as described in relation to Figure 2 and Figure 3 above.
  • a base sequence, SO of length NO with good correlation properties and/or selecting a base sequence SO providing an autocorrelation below a measure and/or threshold, is selected.
  • the length NO may be based on variation of radio characteristics of the channel on which the reference signal is transmitted and/or the length, NO, may be based on the number resource elements (RE) within an OFDM symbol on which a reference signal (e.g DMRS) is allocated and/or transmitted.
  • a reference signal e.g DMRS
  • the sequence S 1 may be obtained and/or generated by applying a transformation, such as e.g. applying a cyclic shift, to the sequence SO in order to obtain a sequence St of length NO.
  • a transformation such as e.g. applying a cyclic shift
  • the sequence S 1 may additionally and/or alternatively be generated and/or obtained by concatenating the elements of sequence Se with Ns- k-NO elements.
  • S I may be obtained by concatenating the sequence Se with Ns- k-NO elements, from an alphabet.
  • S 1 may be obtained by concatenating the Ns- k-NO elements with a truncated version of Se.
  • S 1 may be obtained by concatenating some of the Ns- k-NO elements with Se followed by the remaining of the Ns- k-NO elements.
  • NO may be chosen to be short enough so that the radio channel exhibits good correlation over the length NO. Furthermore, NO may be chosen to match existing codes with desired correlation properties. Other sequences may be obtained by choosing different base sequences and/or applying different transformations (in Step 2) and/or by concatenating different Ns- k-NO additional elements.
  • Barker codes examples of base codes with good correlation properties are the Barker codes and the Gold sequences.
  • a set of Gold code sequences consists of 2n - 1 sequences each one with a period of 2n - 1.
  • a set of Gold codes can be generated or obtained with the following steps. Pick two maximum length sequences of the same length 2n - 1 such that their absolute cross- correlation is less than or equal to 2(n+2)/2, where n is the size of the Linear-Feedback Shift Register (LFSR) used to generate the maximum length sequence.
  • the set of the 2n - 1 exclusive-ors of the two sequences in their various phases (i.e. translated into all relative positions) is a set of Gold codes.
  • the highest absolute cross -correlation in this set of codes is 2(n+2)/2 + 1 for even n and 2(n+l)/2 + 1 for odd n.
  • Barker codes where negations and reversals of the codes have been omitted.
  • a Barker code has a maximum autocorrelation sequence which has sidelobes no larger than 1, are presented in the table below. It is generally accepted that no other perfect binary phase codes exist.
  • a sequence may relate to a code such that a code comprises a set of sequences.
  • Ns is 14, which in this example corresponds to the number of DMRS symbols in an LTE subframe.
  • Example of how a first sequence S 1 of length Ns 14 can be obtained and/or generated:
  • Ns is 14, which in this example corresponds to the number of DMRS symbols in an LTE subframe meaning that a reference signal (e.g. DMRS) is transmitted in each OFDM symbol in the subframe.
  • a reference signal e.g. DMRS
  • SO may e.g. be chosen and/or selected from a set of length-3 sequences with good cross correlation properties (e.g. a Barker code of length 3 [+1 +1 -1]).
  • a cyclic shift to SO another sequence, St may be obtained (e.g. [-1 +1 +1]).
  • an step of creating a sequence Se of length 12 may be obtained by concatenating 4 copies of St (e.g. [-1 +1 +1 -1 +1 +1 -1 +1 +1 -1 +1 +1 +1 +1]).
  • S 1 of length 14 may be obtained by appending one extra element to the beginning and an extra element to the end of Se.
  • the receiver apply a length-3 filter to estimate the channel coefficients from each of the transmitters, separately.
  • the first and last OFDM symbols within the subframe may not have good cross correlation properties. This is not important for in particular V2V communications but also for radio communication using higher carrier frequencies (up to 6 GHz), since the first OFDM symbol is usually lost due to the settling time of the AGC and there is no transmission in the last symbol.
  • the LTE subframe is an example of a transmission time interval in LTE, but can be any other time structure representing a corresponding TTI in any other radio access technology based on OFDM radio communication.
  • the DMRS in this example may be an example of a second sequence, S2.
  • a second, similar, example will be described.
  • This example differs in that the "shift” step follows the "concatenation” step.
  • each concatenated version of the base code e.g SO
  • this example allows for applying a specific shift to each concatenated version of Se.
  • This can be beneficial for implementation of a receiver where each concatenated block (e.g SO and/or Se) is correlated (i.e., processed) independently from other blocks in the channel estimator.
  • having block- specific shifts enables reduction of the probability that all blocks exhibit bad correlation properties with a given interferer.
  • a further example of the method relies on any of the previous examples and provides a solution for the generation of the shifts. It is proposed here that the code and/or sequence shifts are generated as a function of transmission parameters of the UE, possibly together with other parameters which are derived implicitly or signaled by a control node (e.g. an eNB or another wireless device or UE). For example some UE identities can be exploited for deriving the shift of the code and or sequence (for all concatenations or for each specific block).
  • a control node e.g. an eNB or another wireless device or UE.
  • the index of the base code and/or base sequence may be derived as a function of transmission parameters of the UE, possibly together with other parameters which are derived implicitly or signaled by a control node.
  • the shifts for at least a subset of the sequences and/or reference symbols may be generated or obtained as a function of any combination of: ⁇ Time and/or frequency position of resources used for transmitting the control information scheduling the transmission (e.g., a scheduling assignment).
  • a control channel scheduling a transmission which may include: - A number of the transmission of the transmission of a given Transport Block (TB).
  • the ID of the transmitter, receiver, or some other NW node is the ID of the transmitter, receiver, or some other NW node.
  • the ID corresponding to the synchronization reference (e.g., an eNB, GNSS, etc.) used for the transmission.
  • some parameter associated to the pool e.g., an identifier, the size of the pool, etc.
  • the block specific and/or UE specific shifts may even be assigned according to the output of a pseudo-random number generator.
  • the initialization of such generator may be a function of at least any of the parameters listed above in order to enhance interference decorrelation.
  • Concatenating may comprise appending and/or prepending.
  • Transmitting a reference signal may comprise transmitting a series of reference signals in different OFDM symbols.
  • Transmitting a reference signal may also comprise transmitting a signal modulated by a sequence of length Ns in one and/or several symbols within one TTI.
  • Transmitting a reference signal may also comprise transmitting a signal modulated by a sequence of length Ns, e.g. by multiplying a reference signal of Ns reference symbols with the sequence of length Ns, wherein multiplying may comprise a scalar multiplication.
  • a TTI Transmission Time Interval
  • a TTI may pertain to an allocated time period when transmission from a wireless device is scheduled.
  • a TTI may be e.g. a subframe of 1 ms, a part of a subframe, one or more OFDM symbols and/or time slots or mini-time slots as defined in 3 GPP or 3GPP-LTE (4G) or 3GPP-NR (5G).
  • a sequence such as e.g.
  • S I, S2, SO, Se and/or St may pertain to a series and/or sequence of elements, wherein the elements may be e.g. alphanumeric characters, integers, vectors, matrices, binary digits, complex numbers and/or real numbers.
  • a length of a sequence may pertain to the number of elements comprised in the respective sequence.
  • a TTI may comprise one or several OFDM symbols.
  • a subframe in LTE may comprise 14
  • DMRS symbol may represent a OFDM symbol in a TTI in which a DMRS is transmitted.
  • a reference signal may be a reference signal for demodulation, such as e.g. a Demodulation Reference Signal (DMRS) in LTE.
  • DMRS Demodulation Reference Signal
  • a reference signal may be transmitted by a wireless device, in certain symbols (e.g. OFDM symbols as in LTE) in a resource block allocated to the wireless device.
  • a reference signal may be transmitted on all subcarriers allocated to the wireless device, in specified symbols or in a subset of subcarriers allocated for transmission.
  • Radio characteristics in this disclosure may relate to e.g. SINR, SNR, RSSI, RSRQ, RSRP and/or Ec/N.
  • the D2D or sidelink UE or UE 12 may comprise a processing circuit or a processing module or a processor or means 710, antenna circuitry (not shown); a receiver circuit or receiver module 720; a transmitter circuit or transmitter circuit 730; a memory or a memory module 740 and a transceiver circuit or transceiver module 750 which may include the transmitter circuit 730 and the receiver circuit 720.
  • the D2D UE or UE may be referred to as a wireless device e.g. a mobile terminal, wireless terminal, mobile station, mobile telephone, cellular telephone, or a smart phone.
  • a wireless device e.g. a mobile terminal, wireless terminal, mobile station, mobile telephone, cellular telephone, or a smart phone.
  • Further examples of different wireless devices comprise laptops with wireless capability, Laptop Embedded Equipment (LEE), Laptop Mounted Equipment (LME), USB dongles, Customer Premises Equipment (CPE), modems, Personal Digital Assistants (PDA), or tablet computers, sometimes referred to as a surf plates with wireless capability or simply, tablets, Machine-to-Machine (M2M) capable devices or UEs, Machine Type Communication (MTC) devices such as sensors, e.g., a sensor equipped with UE, just to mention some examples.
  • M2M Machine-to-Machine
  • MTC Machine Type Communication
  • a UE is used interchangeably with wireless device and D2D UE throughout this
  • the processing module/circuit 710 includes a processor, microprocessor, an application specific integrated circuit (ASIC), field programmable gate array (FPGA), or the like, and may be referred to as the "processor 710."
  • the processor 710 controls the operation of the D2D UE 12 and its components.
  • Memory (circuit or module) 740 includes a random access memory (RAM), a read only memory (ROM), and/or another type of memory to store data and instructions that may be used by processor 710.
  • RAM random access memory
  • ROM read only memory
  • the D2D UE 700 in one or more embodiments includes fixed or programmed circuitry that is configured to carry out the operations in any of the embodiments disclosed herein.
  • the D2D UE 12 includes a microprocessor, microcontroller, DSP, ASIC, FPGA, or other processing circuitry that is configured to execute computer program instructions from a computer program stored in a non-transitory computer-readable medium that is in, or is accessible to the processing circuitry.
  • non-transitory does not necessarily mean permanent or unchanging storage, and may include storage in working or volatile memory, but the term does connote storage of at least some persistence.
  • the execution of the program instructions specially adapts or configures the processing circuitry to carry out the D2D UE operations disclosed herein.
  • the D2D UE 12 may comprise additional components not shown in Figure 5.
  • the receiver module/circuit 720 (also referred to as a receiver 720 or receiver circuit 720) or the transceiver module/circuit 750 (also referred to as a transmitter 750 or transmitter circuit 750) is adapted and/or configured to transmit a reference signal, the reference signal being based on a first sequence, S 1 and/or a second sequence, S2 and further adapted to generate and/or obtain the sequence, S 1 by performing at least one of the below actions: select a base sequence, SO, of length NO with good correlation properties and/or select a base sequence SO which provides an autocorrelation below a measure and/or threshold; apply a transformation, such as e.g.

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

Abstract

L'invention concerne un procédé de commande d'un équipement d'utilisateur, UE, le procédé comprenant la transmission ou la réception d'un signal de référence, le signal de référence étant basé sur une première séquence, S1, de longueurs N. La première séquence, S1, est obtenue via : la sélection d'une séquence de base, S0, de longueur N0; la création d'une séquence, Se, de longueur k∙N0, où k∙N0 <= Ns; la concaténation de k copies de S0; et l'obtention de la séquence, S1, via la concaténation des éléments d'une séquence Se avec Ns- k∙N0 éléments.
PCT/SE2017/050370 2016-04-12 2017-04-12 Procédé et appareils de génération de signal de référence WO2017180052A1 (fr)

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US62/321,485 2016-04-12

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CN109361431A (zh) * 2018-12-13 2019-02-19 中国科学院计算技术研究所 一种切片的调度方法与系统
CN109359355A (zh) * 2018-09-05 2019-02-19 重庆创速工业有限公司 一种标准结构模块的设计实现方法
WO2019190273A1 (fr) * 2018-03-30 2019-10-03 엘지전자 주식회사 Procédé d'émission ou de réception de signal de liaison latérale par un terminal dans un système de communication sans fil prenant en charge une liaison latérale, et appareil associé
CN111835475A (zh) * 2019-04-19 2020-10-27 华为技术有限公司 发送和接收dmrs的方法和装置

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US20140269641A1 (en) * 2011-11-03 2014-09-18 Lg Electronics Inc. Method for transreceiving reference signal in wireless access system and apparatus for same
US20140286293A1 (en) * 2011-11-24 2014-09-25 Lg Electronics Inc. Method for performing device-to-device communication in wireless access system and apparatus for same

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019190273A1 (fr) * 2018-03-30 2019-10-03 엘지전자 주식회사 Procédé d'émission ou de réception de signal de liaison latérale par un terminal dans un système de communication sans fil prenant en charge une liaison latérale, et appareil associé
US11470613B2 (en) 2018-03-30 2022-10-11 Lg Electronics Inc. Method for transmitting or receiving sidelink signal by terminal in wireless communication system supporting sidelink and apparatus therefor
CN109359355A (zh) * 2018-09-05 2019-02-19 重庆创速工业有限公司 一种标准结构模块的设计实现方法
CN109361431A (zh) * 2018-12-13 2019-02-19 中国科学院计算技术研究所 一种切片的调度方法与系统
CN109361431B (zh) * 2018-12-13 2020-10-27 中国科学院计算技术研究所 一种切片的调度方法与系统
CN111835475A (zh) * 2019-04-19 2020-10-27 华为技术有限公司 发送和接收dmrs的方法和装置

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