WO2018203104A1

WO2018203104A1 - Subframe handling for extra-standard information in ofdm

Info

Publication number: WO2018203104A1
Application number: PCT/IB2017/052526
Authority: WO
Inventors: Leonard Lightstone; Girum FANTAYE
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2017-05-01
Filing date: 2017-05-01
Publication date: 2018-11-08

Abstract

Systems and methods are disclosed herein that enable transmission of extra-standard data (e.g., Antenna Calibration (AC) training data) in an efficient manner that mitigates the impact of the extra-standard data on cell performance. In some embodiments, a method of operation of a radio access node of a wireless communications system comprises obtaining a signal comprising extra-standard data, transmitting the signal via an Adaptive Antenna System (AAS) of the radio access node, receiving the signal via the AAS of the radio access node, and processing the signal received via the AAS.

Description

SUBFRAME HANDLING FOR EXTRA-STANDARD INFORMATION IN OFDM

Technical Field

[0001 ] The present disclosure relates to transmission of extra-standard data within a subframe of a downlink or uplink signal in a wireless communications network.

Background

Adaptive Antenna System (AAS) and Antenna Calibration

[0002] Advanced wireless systems, particularly the later releases of Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) and the Fifth Generation (5G) technologies being currently developed, include AAS as a keystone technology in the push for improved wireless performance and capacity. One consideration unique to AAS is the need to continuously calibrate the antenna elements of the AAS so that digital beamforming can be reliably performed. Calibration may need to be performed in either the downlink

(transmit) or uplink (receive) direction, or both.

[0003] Typically, calibration is performed by sending a known signal pattern, termed training data, to the AAS. The signal as transmitted (or received) by the AAS is detected through the use of special circuitry. The detected signal is compared with the known training data to thereby determine the antenna induced errors (e.g., gain and phase errors for the individual antenna elements of the AAS). These antenna induced errors can subsequently be corrected by calibrating the AAS (e.g., calibrating the AAS to correct the gain and phase errors for the individual antenna elements). By necessity for downlink calibration, the training data is transmitted over the air, but possibly at very low power so that the signal is not perceived by any User Equipment devices (UEs). The training signal must cover the full, or most of the bandwidth of the cell, but most of the remaining details of the training data - for example contiguity in frequency and/or time - can be designed as part of the calibration procedure itself. [0004] The frequency with which the calibration operation must be performed depends primarily on the stability of the components in the radio/antenna system as well as the variability of the environment that the system experiences. Here, it should be noted that there is continuous pressure for the production of low cost systems which generally translates to poorer quality (i.e., less stable)

components.

Adaptive Transmission Coding

[0005] In a typical wireless communications network, the network decides the transmission parameters for the downlink based on the receiver Channel State Information (CSI) report. The transmission parameters include the Modulation and Coding Scheme (MCS), transmit power, transmission mode, and number of transmission layers, etc.

[0006] In 3GPP LTE, the MCS used is typically decided by the number of information bits, or physical layer payload, that can fit in a set of scheduled

Physical Resource Blocks (PRBs) such that the eventual packet transmission is successfully received at the destination with a predefined target probability. The packet error rate depends on the resulting code rate for the transmission, which is defined as the ratio of the information bits to the number of raw bits that are transmitted over the channel. The number of raw bits allocated for the

transmission is dependent on the size of the PRB set and the Resource

Elements (REs) available for data transmission in that PRB set.

Physical Downlink Control Channel (PDCCH)

[0007] The first one to four symbols, depending on the value indicated by the Control Format Indicator (CFI) as well as the cell bandwidth, in an LTE subframe are used to transmit the PDCCH. Control information for a given UE is distributed in groups of Resource Elements (REs) termed Control Channel Elements (CCE). The assignment of CCEs for the different UEs addressed in the PDCCH presents a random-like distribution that changes subframe-to- subframe. CSI Reference Signal (CSI-RS)

[0008] In 3GPP LTE Release 10, new CSI-RS subframes are introduced to support advanced features such as higher order Multiple-lnput-Multiple-Output (MIMO), Multi-user MIMO (MU-MIMO) / beam-forming, Coordinated Multi-Point (CoMP) transmission, etc. In the CSI-RS subframes, new reference symbols are transmitted by the serving cell to assist CSI measurements by UEs with Release 10 capability and beyond.

[0009] Figure 1 illustrates examples of CSI-RS in a resource block pair in an LTE subframe for different CSI-RS configurations. Overhead signals such as the Cell Reference Symbols (CRSs) occupy specific REs. Most REs are available for user data (Downlink Shared Channel (DL-SCH)). The CSI-RSs occupy certain REs that depend on the CSI-RS configuration, as illustrated in Figure 1 . The total set of possible CSI-RS positions is also illustrated in Figure 1 . As can be seen, for any given cell, only a few of the possible CSI-RS positions will be occupied by CSI-RS while the remainder will be either muted or used for DL- SCH. The REs occupied by the CSI-RS are configured in terms of which symbols, tones, and subframes are used. The repeat period for the CSI-RS pattern is also configurable.

[0010] As mentioned above, the CSI-RS may be muted on a cell-by-cell basis. This is done so that the CSI-RSs of neighbor cells are quiet and do not cause interference in the UE detection of the CSI-RS on the serving cell.

[0011 ] Note that all configurations of the CSI-RS cover the entire bandwidth of the signal. Some configurations provide CSI-RS opportunities that are

contiguous in frequency, and some configurations provide CSI-RS opportunities that are not contiguous in frequency.

Summary

[0012] Systems and methods are disclosed herein that enable transmission of extra-standard data (e.g., Antenna Calibration (AC) training data) in an efficient manner that mitigates the impact of the extra-standard data on cell performance. In some embodiments, a method of operation of a radio access node of a wireless communications system comprises obtaining a signal comprising extra- standard data, transmitting the signal via an Adaptive Antenna System (AAS) of the radio access node, receiving the signal via the AAS of the radio access node, and processing the signal received via the AAS.

[0013] In some embodiments, the signal is a downlink signal transmitted by the radio access node. Further, in some embodiments, the extra-standard data is at time-frequency locations within the downlink signal that puncture a shared downlink data channel comprised in the downlink signal. Still further, in some embodiments, a Modulation and Coding Scheme (MCS) used for a downlink transmission to a wireless device in the shared downlink data channel is a function of an effective Signal to Interference plus Noise Ratio (SINR) that accounts for the puncturing of the shared downlink data channel with the extra- standard data. In some other embodiments, the extra-standard data is at time- frequency locations within the downlink signal that are unused within a downlink control region that spans an entire system bandwidth of the downlink signal. In some other embodiments, the extra-standard data is at time-frequency locations within the downlink signal that correspond to muted Channel State Information Reference Signal (CSI-RS) resources. In some other embodiments, the extra- standard data is in symbol periods that are inactive within a subframe structure used for the downlink signal. In this manner, the extra-standard data (e.g., AC training data) is transmitted in an efficient manner that mitigates the impact of the extra-standard data on cell performance.

[0014] In some embodiments, the signal is an auxiliary uplink signal to be combined, at the AAS, with an uplink signal received by the radio access node, and receiving the signal comprises receiving a combined uplink signal comprising the uplink signal and the auxiliary uplink signal. Further, in some embodiments, transmitting the signal comprises transmitting the auxiliary uplink signal such that, when combined with the uplink signal, the extra-standard data is at time- frequency locations within the combined uplink signal that overlap with a shared uplink data channel comprised in the uplink signal. In some other embodiments, transmitting the signal comprises transmitting the auxiliary uplink signal such that, when combined with the uplink signal, the extra-standard data is at time- frequency locations within the combined uplink signal that overlap with time- frequency locations in the uplink signal that may be used for one or more uplink Sounding Reference Signals (SRSs). In some other embodiments, transmitting the signal comprises transmitting the auxiliary uplink signal such that, when combined with the uplink signal, the extra-standard data is in symbol periods in the combined uplink signal that correspond to inactive symbol periods within a subframe structure used for the uplink signal. In this manner, the extra-standard data (e.g., AC training data) is transmitted in an efficient manner that mitigates the impact of the extra-standard data on cell performance.

[0015] In some embodiments, processing the signal received via the AAS comprises extracting the extra-standard data from the signal received via the AAS and processing the extra-standard data.

[0016] In some embodiments, the extra-standard data comprises AC training data.

[0017] Embodiments of a radio access node for a wireless communications system are also disclosed. In some embodiments, a radio access node for a wireless communications system is adapted to perform the method of operation of a radio access node according to any one of the embodiments disclosed herein.

[0018] In some embodiments, a radio access node for a wireless

communications system comprises one or more transmitters, one or more receivers, an AAS coupled to the one or more transmitters and the one or more receivers, and circuitry coupled to the one or more transmitters and the one or more receivers. The circuitry is adapted to obtain a signal comprising extra- standard data, transmit the signal via the AAS and one of the one or more transmitters, receive the signal via the AAS and one of the one or more receivers, and process the signal received via the AAS and the one of the one or more receivers. [0019] In some embodiments, the signal is a downlink signal transmitted by the radio access node. Further, in some embodiments, the extra-standard data is at time-frequency locations within the downlink signal that puncture a shared downlink data channel comprised in the downlink signal. In some embodiments, the circuitry is further adapted to adjust a MCS used for a downlink transmission to a wireless device in the shared downlink data channel as a function of an effective SINR that accounts for the puncturing of the shared downlink data channel with the extra-standard data. In some other embodiments, the extra- standard data is at time-frequency locations within the downlink signal that are unused within a downlink control region that spans an entire system bandwidth of the downlink signal. In some other embodiments, the extra-standard data is at time-frequency locations within the downlink signal that correspond to muted CSI-RS resources. In some other embodiments, the extra-standard data is in symbol periods that are inactive within a subframe structure used for the downlink signal. In this manner, the extra-standard data (e.g., AC training data) is transmitted in an efficient manner that mitigates the impact of the extra- standard data on cell performance.

[0020] In some embodiments, the signal is an auxiliary uplink signal to be combined, at the AAS, with an uplink signal received by the radio access node, and in order to receive the signal, the circuitry is further adapted to receive a combined uplink signal comprising the uplink signal and the auxiliary uplink signal. In some embodiments, when the auxiliary uplink signal is combined with the uplink signal, the extra-standard data is at time-frequency locations within the combined uplink signal that overlap with a shared uplink data channel comprised in the uplink signal. In some other embodiments, when the auxiliary uplink signal is combined with the uplink signal, the extra-standard data is at time-frequency locations within the combined uplink signal that overlap with time-frequency locations in the uplink signal that may be used for one or more uplink SRSs. In some other embodiments, when the auxiliary uplink signal is combined with the uplink signal, the extra-standard data is in symbol periods in the combined uplink signal that correspond to inactive symbol periods within a subframe structure used for the uplink signal. In this manner, the extra-standard data (e.g., AC training data) is transmitted in an efficient manner that mitigates the impact of the extra-standard data on cell performance.

[0021 ] In some embodiments, in order to process the signal received via the AAS, the circuitry is further adapted to extract the extra-standard data from the signal received via the AAS and process the extra-standard data.

[0022] In some embodiments, the extra-standard data comprises AC training data.

[0023] In some embodiments, a radio access node for a wireless

communications system comprises an obtaining module, a transmitting module, a receiving module, and a processing module. The obtaining module is operable to obtain a signal comprising extra-standard data. The transmitting module is operable to transmit the signal via an AAS of the radio access node. The receiving module is operable to receive the signal via the AAS of the radio access node, and the processing module is operable to process the signal received via the AAS.

[0024] Embodiments of a computer program are also disclosed. In some embodiments, a computer program comprises instructions which, when executed on at least one processor, cause the at least one processor to carry out the method of operation of a radio access node according to any one of the embodiments described herein. In some embodiments, a carrier containing the aforementioned computer program is provided, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium.

[0025] Those skilled in the art will appreciate the scope of the present disclosure and realize additional aspects thereof after reading the following detailed description of the embodiments in association with the accompanying drawing figures. Brief Description of the Drawings

[0026] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

[0027] Figure 1 illustrates examples of Channel State Information (CSI) Reference Signal (CSI-RS) in a resource block pair in a Long Term Evolution (LTE) subframe for different CSI-RS configurations;

[0028] Figure 2 illustrates one example of a wireless communications network in which embodiments of the present disclosure may be implemented;

[0029] Figure 3 is a schematic diagram of the radio access node according to some embodiments of the present disclosure;

[0030] Figure 4 illustrates a method of operation of the radio access node in which the radio access node transmits extra-standard data in a downlink signal according to some embodiments of the present disclosure;

[0031 ] Figure 5 illustrates a process for inserting extra-standard data into an uplink signal received by the radio access node according to some other embodiments of the present disclosure;

[0032] Figure 6 is a flow chart that illustrates the operation of the radio access node according to some embodiments of the present disclosure;

[0033] Figures 7 and 8 illustrate example embodiments of a wireless device; and

[0034] Figures 9 and 10 illustrate example embodiments of a radio access node. Detailed Description

[0035] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.

[0036] Radio Node: As used herein, a "radio node" is either a radio access node or a wireless device.

[0037] Radio Access Node: As used herein, a "radio access node" or "radio network node" is any node in a radio access network of a wireless

communications network that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high- power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), and a relay node.

[0038] Core Network Node: As used herein, a "core network node" is any type of node in a core network. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (P- GW), a Service Capability Exposure Function (SCEF), or the like.

[0039] Wireless Device: As used herein, a "wireless device" is any type of device that has access to (i.e., is served by) a wireless communications network by wirelessly transmitting and/or receiving signals to a radio access node(s). Some examples of a wireless device include, but are not limited to, a User Equipment device (UE) in a 3GPP network and a Machine Type Communication (MTC) device.

[0040] Network Node: As used herein, a "network node" is any node that is either part of the radio access network or the core network of a wireless communications network/system.

[0041 ] Extra-Standard Data: As used herein, "extra-standard data" is data inserted into a downlink signal or an uplink signal that is not defined in a corresponding standard. [0042] Adaptive Antenna System (AAS): As used herein, an "adaptive antenna system" or "AAS" is a system that includes many antenna elements that can be adaptively configured to provide beamforming.

[0043] Puncturing: As used herein, "puncturing" is a process by which data in some time-frequency resources of a transmission (e.g., a downlink or uplink shared channel transmission) are replaced with other data (e.g., a reference signal).

[0044] System Bandwidth: As used herein, "system bandwidth" is a total bandwidth of a corresponding downlink or uplink carrier. For instance, in a LTE network, the system bandwidth is in the range of 1 .4 megahertz (MHz) to 20 MHz.

[0045] Muted Channel State Information (CSI) Reference Signal (CSI-RS) Resource: As used herein, a "muted CSI-RS resource" is a resource to which a radio access node does not map Physical Downlink Shared Channel (PDSCH) and in which the radio access node does not transmit any CSI-RS. In other words, in LTE, muted CSI-RS resources are used to facilitate CSI Interference Measurement (CSI-IM).

[0046] Auxiliary Uplink Signal: As used herein, an "auxiliary uplink signal" is a signal generated to include extra-standard data and generated by radio access node on uplink resources. As described herein, an auxiliary uplink signal is combined with an actual uplink signal received by the radio access node such that the resulting uplink signal includes the extra-standard data.

[0047] Note that the description given herein focuses on a 3GPP wireless communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system.

[0048] Note that, in the description herein, reference may be made to the term "cell;" however, particularly with respect to 5G NR concepts, beams may be used instead of cells and, as such, it is important to note that the concepts described herein are equally applicable to both cells and beams. [0049] The problem introduced by the need for Antenna Calibration (AC) training data is that this data must use some of the same time-frequency resources as those intended for existing signals, typically UE data (e.g., data transmitted in the Downlink Shared Channel (DL-SCH)). As a result, the inclusion of the AC training data can negatively impact cell performance. Of course, the overall benefits of AAS are such that the net result of using AAS is improved cell performance relative to not using AAS. However, the desire is to achieve the absolute best cell performance with AAS.

[0050] When AC is a rare event, or if cells are only lightly loaded with traffic, it can be acceptable to steal subframes and dedicate these subframes to carry the AC training data. In other words, no DL-SCH is transmitted in a stolen subframe. However, this approach will cause noticeable cell capacity degradation when AC actions are frequent or when cell loading is high.

[0051 ] Another brute force approach is to puncture the AC training data into existing user data in the Orthogonal Frequency Division Multiplexing (OFDM) subframe. This will result in a decrease in Signal to Interference plus Noise Ratio (SINR) of the received signal and may, in turn, result in the signal not being decodable by the UE. If the signal is not decodable, a retransmit will be required which will have the effect of lowering cell throughput and increasing response latency.

[0052] Systems and methods are disclosed herein that enable transmission of extra-standard data (e.g., AC training data) in an efficient manner that mitigates the impact of the extra-standard data on cell performance. In some

embodiments, a radio access node obtains a signal comprising extra-standard data and transmits the signal via an AAS. The radio access node receives the signal via the AAS. In other words, within the AAS, the output of a transmitter that transmits the signal is coupled to an input of a receiver of the radio access node. The radio access node processes the signal. For example, in some embodiments, the extra-standard data is AC training data, and the radio access node processes the signal to extract the AC training data. The radio access node then calibrates the AAS based on the received AC training data, e.g., as compared to the known transmitted AC training data.

[0053] In some embodiments, the signal comprising the extra-standard data is a downlink signal transmitted by the radio access node. As discussed below in detail, in some embodiments, the extra-standard data signal is:

• at time-frequency locations within the downlink signal that puncture a shared downlink data channel comprised in the downlink signal,

• at time-frequency locations within the downlink signal that are

unused within a downlink control region that spans an entire system bandwidth of the downlink signal (e.g., in unused Control Channel

Elements (CCEs) within the LTE downlink control region),

• at time-frequency locations within the downlink signal that corresponded to muted CSI-RS resources, and/or

• in symbol periods that are inactive within a subframe structure used for the downlink signal.

[0054] In some embodiments, the signal comprising the extra-standard data is an auxiliary uplink signal to be combined, at the AAS, with an uplink signal received by the radio access node, and the radio access node receives a combined uplink signal comprising the uplink signal and the auxiliary uplink signal. In some embodiments, the auxiliary uplink signal is transmitted such that, after combining of the auxiliary uplink signal with the uplink signal in the AAS, the extra-standard data signal is:

• at time-frequency locations within the combined uplink signal that overlap a shared uplink data channel comprised in the uplink signal,

• at time-frequency locations within the combined uplink signal that overlap one or more uplink Sounding Reference Signals (SRSs) comprised in the uplink signal, and/or

• in symbol periods in the combined uplink signal that correspond to inactive symbol periods within a subframe structure used for the uplink signal. [0055] In this regard, Figure 2 illustrates one example of a wireless

communications network 10 in which embodiments of the present disclosure may be implemented. In some embodiments, the wireless communications network 10 is a 5G network, which is also referred to as a NR network; however, the present disclosure is not limited thereto. As illustrated, a number of wireless devices 12 (e.g., UEs) wirelessly transmit signals to and receive signals from radio access nodes 14 (e.g., gNBs, which are 5G NR base stations), each serving one or more cells 16. The radio access nodes 14 are connected to a core network 18. As discussed below in detail, the radio access nodes 14 transmit extra-standard data (e.g., AC training data).

[0056] Figure 3 is a schematic diagram of a radio access node 14 according to some embodiments of the present disclosure. As illustrated, the radio access node 14 includes a control unit 20 implemented as a combination of hardware and software and a radio unit 22. The control unit 20 includes a control and processing system 24, which includes circuitry such as, e.g., one or more processors (e.g., a Central Processing Unit(s) (CPU(s)), a Digital Signal

Processor(s) (DSP(s)), an Application Specific Integrated Circuit(s) (ASIC(s)), a Field Programmable Gate Array(s) (FPGA(s)), and/or the like), memory storing software executable by the processor(s) to perform the functions of the radio access node 14 described herein, etc. The control unit 20 may also include a network interface 26 (e.g., an Ethernet interface) that enables the radio access node 14 to communicate with other network nodes such as, e.g., other radio access nodes 14 and/or the core network 18.

[0057] The radio unit 22 includes a main transmitter 28, a main receiver 30, and an AAS 32. The main transmitter 28 has an input coupled to the control unit 20 and an output coupled to the AAS 32. The main transmitter 28 includes one or more transmit chains, each including circuitry such as, e.g., amplifiers, mixers, filters, and/or the like. Likewise, the main receiver 30 has an input coupled to the AAS 32 and an output coupled to the control unit 20. The main receiver 30 includes one or more receive chains, each including circuitry such as, e.g., amplifiers, mixers, filters, and/or the like. [0058] More specifically, in one example embodiment, the main transmitter 28 includes N transmit chains, the main receiver 30 includes N receive chains, and the AAS 32 includes N antennas coupled to the N outputs of the N transmit chains of the main transmitter 28 and to the N inputs of the N receive chains of the main receiver 30 via a corresponding switching network (e.g., duplex filters). Further, in some embodiments, the AAS 32 includes calibration circuitry that operates to provide gain and/or phase adjustments for each antenna element, where the gain and/or phase adjustments are configured by the control and processing system 24 to mitigate gain and/or phase errors in the AAS 32, as determined through an appropriate AC procedure.

[0059] In some embodiments, the radio unit 22 includes an auxiliary transmitter 34 and/or an auxiliary receiver 36. The auxiliary transmitter 34 includes, e.g., a single transmit chain that includes circuitry such as, e.g., amplifiers, mixers, filters, etc. The input of the auxiliary transmitter 34 is coupled to the control unit 20 and the output of the auxiliary transmitter 34 is coupled to the AAS 32. The auxiliary receiver 36 includes, e.g., a single receive chain that includes circuitry such as, e.g., amplifiers, mixers, filters, etc. The input of the auxiliary receiver 36 is coupled to the AAS 32 and the output of the auxiliary receiver 36 is coupled to the control unit 20.

[0060] Embodiments of the operation of the radio access node 14 to communicate extra-standard data (e.g., AC training data) will now be described with respect to Figures 4 through 6. Figure 4 illustrates a method of operation of the radio access node 14 in which the radio access node 14 transmits extra- standard data in a downlink signal according to some embodiments of the present disclosure. As illustrated, the radio access node 14, and in particular the control and processing system 24 of the radio access node 14, obtains a downlink signal that comprises extra-standard data (step 100). In some embodiments, the control and processing system 24 generates the downlink signal. As one example alternative, the control and processing system 24 receives the downlink signal from another network node. The radio access node 14 transmits the downlink signal via the main transmitter 28 and the AAS 32 (step 102). Within the downlink signal, the extra-standard data signal is:

• at time-frequency locations within the downlink signal that puncture a shared downlink data channel comprised in the downlink signal, · at time-frequency locations within the downlink signal that are

unused within a downlink control region that spans an entire system bandwidth of the downlink signal (e.g., in unused CCEs within the LTE downlink control region),

Each of these embodiments is described below in detail.

[0061 ] The radio access node 14 also receives the downlink signal via the AAS 32 and either the main receiver 30 or the auxiliary receiver 36, depending on the particular embodiment (step 104). For example, for a Frequency Division Duplexing (FDD) system, downlink and uplink carriers are in different frequency bands. In this case, the auxiliary receiver 36 can be tuned to the downlink frequency band in order to receive the downlink signal including the extra- standard data. As another example, for a Time Division Duplexing (TDD) system, downlink and uplink share the same frequency band. In this case, the main receiver 30 may be utilized to receive the downlink signal including the extra-standard data during a downlink time period. Alternatively, the auxiliary receiver 36 may be used even for a TDD system to receive the downlink signal including the extra-standard data.

[0062] The radio access node 14 processes the downlink signal received via the AAS 32 (step 106). In some embodiments, the radio access node 14, and in particular the control and processing system 24, extracts the extra-standard data from the received downlink signal (step 106A) and processes the extra-standard data (step 106B). For example, in embodiments in which the extra-standard data is AC training data, the control and processing system 24 may utilize the received extra-standard data to perform downlink calibration of the AAS 32.

However, in some alternative embodiments, the control and processing system 24 processes the received downlink signal to, e.g., extract the extra-standard data and provide the extra-standard data to another network node via the network interface 26.

[0063] Note that, in some alternative embodiments, steps 104 and 106 are not performed. For instance, if the transmission of the extra-standard data is to be utilized by another network node (e.g., another radio access node 14 or a wireless device 12), then steps 104 and 106 may not be performed.

[0064] A detailed discussion of each of the embodiments given above for the location of the extra-standard data within the downlink signal will now be provided.

[0065] As discussed above, in some embodiments, the extra-standard data is at time-frequency locations within the downlink signal that puncture a shared downlink data channel comprised in the downlink signal. More specifically, in some embodiments, the extra-standard data (e.g., AC training data) is punctured (i.e., overwrites) scheduled user data in the shared downlink data channel (e.g., PDSCH for LTE). Since the extra-standard data normally only requires a fraction of a subframe, many time-frequency resource elements remain available in the subframe to carry user data.

[0066] The puncturing of the user data effectively reduces the signal power. In some embodiments, the extra-standard data is transmitted over the air at low power and is not perceived by the wireless devices 12. In this case, the puncturing action will not significantly increase the noise level. However, in some other embodiments, the extra-standard data may be transmitted over the air at high power (e.g., at a power level that is perceived by at least some of the wireless devices 12). In this case, the puncturing action may significantly increase the interference level at the wireless devices 12. As discussed below, the Modulation and Coding Scheme (MCS) for the downlink signal may be adjusted to compensate for the increase in interference level due to puncturing. In other words, the MCS for the downlink signal may be a function of an effective SINR that accounts for the puncturing of the shared downlink channel with the extra-standard data.

[0067] Legacy wireless devices 12 measure downlink Channel Quality Indicator (CQI) based on the Cell Reference Signal (CRS) transmitted by its serving cell. The SINR, γ, at the receiver of a wireless device 12 can be estimated based on the CQI report received from the wireless device 12. The estimated SINR for an ith wireless device 12 can be expressed as the ratio of power of the useful signal, S to the power of the unwanted interference plus noise, I + N. ^) = o¾ (D

The effective SINR, y_eff i) , due to the puncturing of the extra-standard data into some of the Resource Elements (REs) of the PDSCH symbol transmission can be expressed as follows:

where n_RE is the number REs for data transmission within a scheduling block without puncturing, i.e. in a normal subframe, and n_P is the number of REs punctured for the extra-standard data.

[0068] In the case where the transmission power for the punctured extra- standard data is significant relative to the user data, the above equations should be modified to represent the punctured data as an additional interference contribution.

^Ye^ ^{l) - n_RE(N₊l)₊n_PS_AC ^> where S_AC is the transmission power of the extra-standard data.

[0069] By adjusting the MCS for the effective SINR, the subframe can be used to carry both user data and the extra-standard data with predictable performance. Thus, in some embodiments, the radio access node 14 adjusts the MCS for user data transmissions that are punctured by the extra-standard data based on the effective SINR.

[0070] In some other embodiments, the extra-standard data signal is at time- frequency locations within the downlink signal that are unused within a downlink control region that spans an entire system bandwidth of the downlink signal (e.g., in unused CCEs within the LTE downlink control region). More specifically, in some embodiments, the extra-standard data uses REs corresponding to unassigned CCEs in the downlink control region. This would be more

complicated than the method above as the pattern occupied by the training data would be irregular across the time-frequency region assigned to the Physical Downlink Control Channel (PDCCH). This irregular distribution would have three byproducts:

• First, it would require a more complicated scheduling activity to identify the subset of available CCEs, or portions of CCEs, in which to insert the extra-standard data.

• Second, in embodiments in which the extra-standard data is AC training data, the location of this data would need to be communicated to the AC system in the radio/antenna complex. This communication will not impact over-the-air resources, but will add extra communication bandwidth between the scheduler element and the radio/antenna calibration element.

• Third, in embodiments in which the extra-standard data is AC

training data, the irregular placement of the AC training data may make the calibration processing more difficult.

Of course, for general extra-standard type content the above issues may have lesser or greater importance.

[0071 ] This technique would result in no reduction of cell capacity. If the signals are transmitted at low power there will be negligible additional

interference to the downlink control channels (e.g., PDCCHs for LTE) of adjacent cells. However, even if there is some incremental increase in interference for those subframes carrying the extra-standard data signals, the randomized use of REs combined with a relatively low frequency of occurrence of these subframes should ensure that any impacts of inserting the extra-standard data signals will be minimal. [0072] In some other embodiments, the extra-standard data signal is at time- frequency locations within the downlink signal that corresponded to muted CSI- RS resources. The CSI-RSs provide a convenient set of configurable REs that cover the full bandwidth used by the cell. Inserting extra-standard data such as AC training data into muted CSI-RS provides a simple means to periodically inject extra-standard data with no loss in cell throughput and no requirement to adjust the transmitted MCS. Further, because CSI-RS cover the full bandwidth (i.e., the system bandwidth), muted CSI-RSs are particularly well-suited for AC training data since AC is desired over the full system bandwidth. Even if the extra-standard data is sent at a power comparable to that of the DL-SCH, the wireless device 12 knows to ignore all locations identified for muted CSI-RS. A high signal strength for the extra-standard data could cause interference for CSI- RS in adjacent cells, but this interference is controllable through proper cell configuration planning. However, for the specific case of AC training data, recall that this data is, in some embodiments, sent at very low power so that, even when present, the AC training data contributes an insignificant amount of interference.

[0073] The CSI-RS muting pattern must be designed to work for both the inter-cell interference reduction and AC requirements. Such considerations should fall within the realm of a normal cell planning exercise.

[0074] In some other embodiments, the extra-standard data signal is in symbol periods that are inactive within a subframe structure used for the downlink signal. More specifically, U.S. Patent Application Publication No.

2015/0023235 A1 entitled FLEXIBLE DOWNLINK SUBFRAME STRUCTURE FOR ENERGY-EFFICIENT TRANSMISSION (hereinafter the '235 Application), which is hereby incorporated herein by reference for its teaching on the configuration of inactive symbol periods within a subframe structure, teaches the configuration and use of subframe structures in which individual OFDM symbols in a subframe are inactive, meaning that no signal is transmitted during at least part of the symbol time of the inactive symbol. In some embodiments, the '235 Application teaches that the base station includes a codeword in the first OFDM symbol of a downlink subframe that indicates that the downlink subframe includes at least one inactive symbol time. The subframe structure

corresponding to the codeword can be, e.g., signaled via a prior broadcast message or predefined for that codeword. In some embodiments, the '235 Application teaches a technique to extend the LTE standard and allow

transmission of the DL-SCH on a partial set of symbols, less than 1 1 , within a subframe. The '235 Application includes a method for dynamic communication of the subframe format with the UE by extending the Physical Control Format Indicator Channel (PCFICH).

[0075] Thus, in some embodiments, the radio access node 14 configures a downlink subframe structure to use a subframe structure that includes one or more inactive symbols, or inactive symbol times, e.g., in accordance with the teachings of the '235 Application. The extra-standard data is transmitted in the inactive symbol(s).

[0076] While Figure 4 illustrates a process for transmitting extra-standard data in a downlink signal, Figure 5 illustrates a process for inserting extra-standard data into an uplink signal received by the radio access node 14 according to some other embodiments of the present disclosure. As illustrated, the radio access node 14, and in particular the control and processing system 24 of the radio access node 14, obtains an auxiliary uplink signal that comprises extra- standard data (step 200). In some embodiments, the control and processing system 24 generates the auxiliary uplink signal. As one example alternative, the control and processing system 24 receives the auxiliary uplink signal from another network node. The radio access node 14 transmits the auxiliary uplink signal via the main transmitter 28 or, alternatively, the auxiliary transmitter 34 and the AAS 32 (step 202). Note that "transmission" of the auxiliary uplink signal refers to the processing of the auxiliary uplink signal via the main transmitter 28 or the auxiliary transmitter 34, depending on the embodiment, and providing the output of the transmitter 28, 34 to the AAS 32. Within the AAS 32, the auxiliary uplink signal is combined with an actual uplink signal (if present) received by the radio access node 14. The auxiliary uplink signal is provided such that, once combined with the uplink signal received by the radio access node 14, the extra- standard data signal is:

• at time-frequency locations within the combined uplink signal that overlap with a shared uplink data channel and/or an uplink control channel comprised in the uplink signal,

• at time-frequency locations within the combined uplink signal that overlap with time-frequency locations in the uplink signal that may be used for one or more uplink SRSs, and/or

• in symbol periods in the combined uplink signal that correspond to inactive symbol periods within a subframe structure used for the uplink signal.

Each of these embodiments is described below in detail.

[0077] The radio access node 14 also receives the auxiliary uplink signal and, in particular the combined uplink signal resulting from the combination of the auxiliary uplink signal and the actual uplink signal received by the radio access node 14, via the AAS 32 and the main receiver 30 (step 204). For example, for a FDD system, downlink and uplink carriers are in different frequency bands. In this case, the auxiliary transmitter 34 can be tuned to the uplink frequency band in order to transmit the auxiliary uplink signal including the extra-standard data. As another example, for a TDD system, downlink and uplink share the same frequency band. In this case, the main transmitter 28 may be utilized to transmit the auxiliary uplink signal including the extra-standard data during an uplink time period. Alternatively, the auxiliary transmitter 34 may be used even for a TDD system to transmit the auxiliary uplink signal including the extra-standard data.

[0078] The radio access node 14 processes the combined uplink signal received via the AAS 32 (step 206). In some embodiments, the radio access node 14, and in particular the control and processing system 24, extracts the extra-standard data from the received combined uplink signal (step 206A) and processes the extra-standard data (step 206B). For example, in embodiments in which the extra-standard data is AC training data, the control and processing system 24 may utilize the received extra-standard data to perform uplink calibration of the AAS 32. However, in some alternative embodiments, the control and processing system 24 processes the received combined uplink signal to, e.g., extract the extra-standard data and provide the extra-standard data to another network node via the network interface 26.

[0079] Note that, in some alternative embodiments, steps 204 and 206 are not performed. For instance, if the transmission of the extra-standard data is to be utilized by another network node (e.g., another radio access node 14 or a wireless device 12), then steps 204 and 206 may not be performed.

[0080] A detailed discussion of each of the embodiments given above for the location of the extra-standard data within the combined uplink signal will now be provided.

[0081 ] In some embodiments, the auxiliary uplink signal is provided such that, once combined with the uplink signal received by the radio access node 14, the extra-standard data signal is at time-frequency locations within the combined uplink signal that overlap with a shared uplink data channel (e.g., Physical Uplink Shared Channel (PUSCH) in LTE) and/or an uplink control channel (e.g.,

Physical Uplink Control Channel (PUCCH) in LTE) comprised in the uplink signal. More specifically, in some embodiments, the extra-standard data (e.g., AC training data) is added on top of scheduled user data in the shared uplink data channel (e.g., PUSCH in LTE) and/or in the uplink control channel (e.g., PUCCH in LTE).

[0082] The transmission of the extra-standard data signal on time-frequency locations that overlap with the shared uplink data channel and/or the uplink control channel effectively reduces the SINR. In some embodiments, the auxiliary uplink signal including the extra-standard data is transmitted at low power. In this case, the transmission of the extra-standard data will not significantly increase the noise level for the received uplink signal. However, in some other embodiments, the auxiliary uplink signal including the extra-standard data may be transmitted at high power. In this case, the transmission of the extra-standard data may significantly increase the noise level for the received uplink signal at the radio access node 14. The MCS for the uplink signal may be adjusted to compensate for the increase in noise level due to the transmission of the extra-standard data based on the effective SINR in a manner similar to that described above for the downlink embodiments. In this situation, the PUCCH region can be excluded from use for transmission of the extra-standard data. If the extra-standard data also covers the PUCCH region, decoding of the PUCCH can be attempted where PUCCH coding is generally robust enough to defeat the interference added by the extra-standard data. The transmit power and/or the amount of extra-standard data may be controlled to enable successful PUCCH decoding.

[0083] In some embodiments, the auxiliary uplink signal is provided such that, once combined with the uplink signal received by the radio access node 14, the extra-standard data signal is at time-frequency locations within the combined uplink signal that overlap with time-frequency locations in the uplink signal that may be used for one or more uplink SRS. SRS may not always be present and, therefore, provide optional empty space in which the extra-standard data may be transmitted. This requires coordination with the uplink scheduling function. More specifically, in some embodiments, the technique is to force occurrences of empty uplink symbols through use of the uplink SRS for the cell. The extra- standard data can be inserted in this empty symbol(s). In LTE, the uplink SRS opportunities may be defined as periodic occurrences for each cell, and UE opportunities for transmitting SRS are assigned in frequency, time, and cyclic shift to each UE to provide a unique opportunity for that UE to transmit its SRS. The UE is silent when not transmitting an SRS during a cell SRS opportunity. Reserving one of the SRS cell opportunities for extra-standard data provides one method to obtain a quiet uplink free of UE transmissions.

[0084] Note that the structure of the PUCCH in a subframe containing the SRS is such that the PUCCH channel does not impact the symbol carrying the SRS. Therefore, the extra-standard data may be placed across the entire bandwidth of the carrier without interfering with user information. This is particularly beneficial in embodiments in which the extra-standard data is AC training data. [0085] In some embodiments, the auxiliary uplink signal is provided such that, once combined with the uplink signal received by the radio access node 14, the extra-standard data signal is in symbol periods in the combined uplink signal that correspond to inactive symbol periods within a subframe structure used for the uplink signal. More specifically, in some embodiments, the teachings of the '235 Application are extended to enable configuration of the uplink subframe structure to include one or more inactive OFDM symbols, or inactive symbol times. For example, the radio access node 14 transmits a codeword in the first OFDM symbol of a downlink subframe to indicate that a corresponding uplink subframe (e.g., the uplink subframe occurring at the same time or an uplink subframe at a predefined or preconfigured offset from the current downlink subframe) has a subframe structure that includes one or more inactive OFDM symbols, meaning that no uplink signal is transmitted during at least part of the symbol time of the inactive symbol. The subframe structure corresponding to the codeword can be, e.g., signaled via a prior broadcast message or predefined for that codeword.

[0086] Thus, in some embodiments, the radio access node 14 configures an uplink subframe structure that includes one or more inactive symbols, or inactive symbol times. The extra-standard data is transmitted in the inactive symbol(s).

[0087] While some examples are given above, the extra-standard data may alternatively be inserted into the uplink signal in other ways. For example, the radio access node 14, or some other network node, may schedule uplink transmissions to avoid certain uplink resources (i.e., time-frequency locations) in the uplink shared channel (e.g., PUSCH), and the extra-standard data may be inserted into at least some of those uplink resources for which scheduling of uplink transmissions is avoided. As another example, uplink control channel transmissions may be avoided in a subframe(s), and the extra-standard data may be inserted into at least some of the uplink control channel resources in that subframe(s). As another example, in a TDD system, extra-standard data may be inserted into the guard time in the special subframe.

[0088] Note that while many of the embodiments described herein are described with respect to LTE, many of these embodiments may also apply to 5G, or NR, networks. Further, in NR, the PUCCH occupies a full symbol in the Transmit Time Interval (TTI). Further, a PUCCH symbol can be explicitly scheduled as needed or desired but does not need to include any user data. Thus, in some embodiments, the extra-standard data may be inserted into a dynamically scheduled PUCCH symbol. Other opportunities for transmitting extra-standard data in NR include, e.g., the use of "mini-slots," empty symbols, or the like. For instance, empty symbols, or empty symbol times, may be

configured in the NR slot and potentially be used for transmission of extra- standard data in either the downlink or the uplink.

[0089] Figure 6 is a flow chart that illustrates the operation of the radio access node 14 according to some embodiments of the present disclosure. This process is a generalization of the processes of Figures 4 and 5. As illustrated, the radio access node 14, and in particular the control and processing system 24 of the radio access node 14, obtains a signal that comprises extra-standard data (step 300). As discussed above, in some embodiments, the signal is a downlink signal that comprises extra-standard data. In other embodiments, the signal is an auxiliary uplink signal that comprises the extra-standard data. In some embodiments, the control and processing system 24 generates the signal. As one example alternative, the control and processing system 24 receives the signal from another network node. The radio access node 14 transmits the signal via the main transmitter 28 or the auxiliary transmitter 34 and the AAS 32, depending on the particular embodiment (step 302).

[0090] The radio access node 14 receives the signal via the AAS 32 and either the main receiver 30 or the auxiliary receiver 36, depending on the particular embodiment (step 304). More specifically, within the AAS 32, the signal is coupled to the input of either the main receiver 30 or the auxiliary receiver 36, depending on the particular embodiment. For the downlink embodiment, the signal is received by the main receiver 30 or the auxiliary receiver 36, depending on the particular embodiment. However, for the uplink embodiment, the timing of the signal is such that the signal is combined with a received uplink signal (if present) in such a manner that the extra-standard data is inserted into the received uplink signal, thereby providing a combined signal to the input of the main receiver 30 or the auxiliary receiver 36, depending on the particular embodiment. As discussed above, for the downlink embodiments, the extra-standard data is:

• at time-frequency locations within the downlink signal that are

Conversely, for the uplink embodiments, the (auxiliary uplink) signal is combined with an actual uplink signal (if present) received by the radio access node 14. The auxiliary uplink signal is provided such that, once combined with the uplink signal received by the radio access node 14, the extra-standard data signal is:

• at time-frequency locations within the combined uplink signal that overlap (i.e., are on top of) a shared uplink data channel and/or an uplink control channel comprised in the uplink signal,

• at time-frequency locations within the combined uplink signal that overlap (i.e., are on top of) one or more uplink SRSs comprised in the uplink signal, and/or

[0091 ] The radio access node 14 processes the combined uplink signal received via the AAS 32 (step 306). In some embodiments, the radio access node 14, and in particular the control and processing system 24 extracts the extra-standard data from the received signal (step 306A) and processes the extra-standard data (step 306B). For example, in embodiments in which the extra-standard data is AC training data, the control and processing system 24 may utilize the received extra-standard data to perform calibration of the AAS 32. However, in some alternative embodiments, the control and processing system 24 processes the received signal to, e.g., extract the extra-standard data and provide the extra-standard data to another network node via the network interface 26.

[0092] Note that, in some alternative embodiments, steps 304 and 306 are not performed. For instance, if the transmission of the extra-standard data is to be utilized by another network node (e.g., another radio access node 14 or a wireless device 12), then steps 304 and 306 may not be performed.

[0093] Figure 7 is a schematic block diagram of the wireless device 12 (e.g., UE) according to some embodiments of the present disclosure. As illustrated, the wireless device 12 includes circuitry 38 comprising one or more processors 40 (e.g., CPUs, ASICs, FPGAs, DSPs, and/or the like) and memory 42. The wireless device 12 also includes one or more transceivers 44 each including one or more transmitters 46 and one or more receivers 48 coupled to one or more antennas 50. In some embodiments, the functionality of the wireless device 12 described herein may be implemented in hardware (e.g., via hardware within the circuitry 38 and/or within the processor(s) 40) or be implemented in a

combination of hardware and software (e.g., fully or partially implemented in software that is, e.g., stored in the memory 42 and executed by the processor(s) 40).

[0094] In some embodiments, a computer program including instructions which, when executed by the at least one processor 40, causes the at least one processor 40 to carry out at least some of the functionality of the wireless device 12 according to any of the embodiments described herein is provided. In some embodiments, a carrier containing the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory). [0095] Figure 8 is a schematic block diagram of the wireless device 12 (e.g., UE) according to some other embodiments of the present disclosure. The wireless device 12 includes one or more modules 52, each of which is

implemented in software. The module(s) 52 provide the functionality of the wireless device 12 described herein.

[0096] Figure 9 is a schematic block diagram that illustrates a virtualized embodiment of the radio access node 14 according to some embodiments of the present disclosure. As used herein, a "virtualized" radio access node 14 is a radio access node 14 in which at least a portion of the functionality of the radio access node 14 is implemented as a virtual component (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, the radio access node 14 optionally includes the control unit 20, as described above with respect to Figure 3. In addition, if the radio access node 14 includes the radio unit 22, as described above with respect to Figure 3. The control unit 20 (if present) is connected to one or more processing nodes 54 coupled to or included as part of a network(s) 56 via the network interface 26. Alternatively, if the control unit 20 is not present, the radio unit 22 is connected to the one or more processing nodes 54 via a network interface(s). Each processing node 54 includes one or more processors 58 (e.g., CPUs, ASICs, DSPs, FPGAs, and/or the like), memory 60, and a network interface 62.

[0097] In this example, functions 64 of the radio access node 14 described herein are implemented at the one or more processing nodes 54 or distributed across the control unit 20 (if present) and the one or more processing nodes 54 in any desired manner. In some particular embodiments, some or all of the functions 64 of the radio access node 14 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 54. As will be appreciated by one of ordinary skill in the art, additional signaling or

communication between the processing node(s) 54 and the control unit 20 (if present) or alternatively the radio unit 22 is used in order to carry out at least some of the desired functions. [0098] In some particular embodiments, higher layer functionality (e.g., layer 3 and up and possibly some of layer 2 of the protocol stack) of the radio access node 14 may be implemented at the processing node(s) 54 as virtual

components (i.e., implemented "in the cloud") whereas lower layer functionality (e.g., layer 1 and possibly some of layer 2 of the protocol stack) may be implemented in the radio unit 22 and possibly the control unit 20.

[0099] In some embodiments, a computer program including instructions which, when executed by the at least one processor (e.g., at least one processor in the control and processing system 24 and/or the at least one processor 58 of the processing node 54) causes the at least one processor to carry out the functionality of the radio access node 14 or a processing node 54 according to any of the embodiments described herein is provided. In some embodiments, a carrier containing the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory included in the control and processing system 24 and/or the memory 60).

[0100] Figure 10 is a schematic block diagram of the radio access node 14 according to some other embodiments of the present disclosure. The radio access node 14 includes one or more modules 66, each of which is implemented in software. The module(s) 66 provide the functionality of the radio access node 14 described herein. In some embodiments, the module(s) 66 may comprise, for example, an obtaining module 66-1 operable to perform the function of step 100 of Figure 4, step 200 of Figure 5, or step 300 of Figure 6; a transmitting module 66-2 operable to perform the function of step 102 of Figure 4, step 202 of Figure 5, or step 302 of Figure 6; a receiving module 66-3 operable to perform the function of step 104 of Figure 4, step 204 of Figure 5, or step 304 of Figure 6; and a processing module 66-4 operable to perform the function of step 106 of Figure 4, step 206 of Figure 5, or step 306 of Figure 6.

[0101 ] The following acronyms are used throughout this disclosure.

• 3GPP Third Generation Partnership Project • 5G Fifth Generation

• AAS Adaptive Antenna System

• AC Antenna Calibration

• ASIC Application Specific Integrated Circuit

• CCE Control Channel Element

• CFI Control Format Indicator

• CoMP Coordinated Multi-Point

• CPU Central Processing Unit

• CQI Channel Quality Indicator

• CRS Cell Reference Signal

• CSI Channel State Information

• CSI-IM Channel State Information Interference Measurement

• CSI-RS Channel State Information Reference Signal

• DL-SCH Downlink Shared Channel

• DSP Digital Signal Processor

• eNB Enhanced or Evolved Node B

• FDD Frequency Division Duplexing

• FPGA Field Programmable Gate Array

• gNB New Radio Base Station

• LTE Long Term Evolution

• MCS Modulation and Coding Scheme

• MHz Megahertz

• MIMO Multiple-lnput-Multiple-Output

• MME Mobility Management Entity

• MTC Machine Type Communication

• MU-MIMO Multi-User Multiple-lnput-Multiple-Output

• NR New Radio

• OFDM Orthogonal Frequency Division Multiplexing

• PCFICH Physical Control Format Indicator Channel

• PDCCH Physical Downlink Control Channel PDSCH Physical Downlink Shared Channel

P-GW Packet Data Network Gateway

PRB Physical Resource Block

PUCCH Physical Uplink Control Channel

PUSCH Physical Uplink Shared Channel

RE Resource Element

SCEF Service Capability Exposure Function

SINR Signal to Interference plus Noise Ratio

SRS Sounding Reference Signal

TDD Time Division Duplexing

TTI Transmit Time Interval

UE User Equipment

[0102]Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

Claims What is claimed is:

1 . A method of operation of a radio access node (14) of a wireless communications system (10), comprising:

obtaining (100, 200, 300) a signal comprising extra-standard data;

transmitting (102, 202, 302) the signal via an adaptive antenna system (32) of the radio access node (14);

receiving (104, 204, 304) the signal via the adaptive antenna system (32) of the radio access node (14); and

processing (106, 206, 306) the signal received via the adaptive antenna system (32).

2. The method of claim 1 wherein the extra-standard data is comprised in the signal in such a manner that mitigates an impact of the extra-standard data on cell performance.

3. The method of claim 1 wherein the signal is a downlink signal transmitted by the radio access node (14).

4. The method of claim 3 wherein the extra-standard data is at time- frequency locations within the downlink signal that puncture a shared downlink data channel comprised in the downlink signal.

5. The method of claim 4 wherein a modulation and coding scheme used for a downlink transmission to a wireless device (12) in the shared downlink data channel is a function of an effective Signal to Interference plus Noise Ratio, SINR, that accounts for the puncturing of the shared downlink data channel with the extra-standard data.

6. The method of claim 3 wherein the extra-standard data is at time- frequency locations within the downlink signal that are unused within a downlink control region that spans an entire system bandwidth of the downlink signal.

7. The method of claim 3 wherein the extra-standard data is at time- frequency locations within the downlink signal that corresponded to muted Channel State Information Reference Signal, CSI-RS, resources.

8. The method of claim 3 wherein the extra-standard data is in symbol periods that are inactive within a subframe structure used for the downlink signal.

9. The method of claim 1 wherein:

the signal is an auxiliary uplink signal to be combined, at the adaptive antenna system (32), with an uplink signal received by the radio access node (14); and

receiving (104, 204, 304) the signal comprises receiving (204) a combined uplink signal comprising the uplink signal and the auxiliary uplink signal.

10. The method of claim 9 wherein transmitting (102, 202, 302) the signal comprises transmitting (202) the auxiliary uplink signal such that, when combined with the uplink signal, the extra-standard data is at time-frequency locations within the combined uplink signal that overlap with a shared uplink data channel comprised in the uplink signal.

1 1 . The method of claim 9 wherein transmitting (102, 202, 302) the signal comprises transmitting (202) the auxiliary uplink signal such that, when combined with the uplink signal, the extra-standard data is at time-frequency locations within the combined uplink signal that overlap with time-frequency locations in the uplink signal that may be used for one or more uplink sounding reference signals.

12. The method of claim 9 wherein transmitting (102, 202, 302) the signal comprises transmitting (202) the auxiliary uplink signal such that, when combined with the uplink signal, the extra-standard data is in symbol periods in the combined uplink signal that correspond to inactive symbol periods within a subframe structure used for the uplink signal.

13. The method of any one of claims 1 to 12 wherein processing (106, 206, 306) the signal received via the adaptive antenna system (32) comprises extracting (106A, 206A, 306A) the extra-standard data from the signal received via the adaptive antenna system (32) and processing (106B, 206B, 306B) the extra-standard data.

14. The method of any one of claims 1 to 13 wherein the extra-standard data comprises adaptive antenna system training data.

15. A radio access node (14) for a wireless communications system (10), the radio access node (14) adapted to perform the method of any one of claims 1 to 14.

16. A computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of claims 1 to 14.

17. A carrier containing the computer program of claim 16, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium.

18. A radio access node (14) for a wireless communications system (10), comprising:

one or more transmitters (28, 34);

one or more receivers (30, 36); an adaptive antenna system (32) coupled to the one or more transmitters (28, 34) and the one or more receivers (30, 36); and

circuitry (24, 58) coupled to the one or more transmitters (28, 34) and the one or more receivers (30, 36), the circuitry (24, 58) adapted to:

obtain a signal comprising extra-standard data;

transmit the signal via the adaptive antenna system (32) and one of the one or more transmitters (28, 34);

receive the signal via the adaptive antenna system (32) and one of the one or more receivers (30, 36); and

process the signal received via the adaptive antenna system (32) and the one of the one or more receivers (30, 36).

19. The radio access node (14) of claim 18 wherein the signal is a downlink signal transmitted by the radio access node (14).

20. The radio access node (14) of claim 19 wherein the extra-standard data is at time-frequency locations within the downlink signal that puncture a shared downlink data channel comprised in the downlink signal.

21 . The radio access node (14) of claim 20 wherein the circuitry (24, 58) is further adapted to adjust a modulation and coding scheme used for a downlink transmission to a wireless device (12) in the shared downlink data channel as a function of an effective Signal to Interference plus Noise Ratio, SINR, that accounts for the puncturing of the shared downlink data channel with the extra- standard data.

22. The radio access node (14) of claim 19 wherein the extra-standard data is at time-frequency locations within the downlink signal that are unused within a downlink control region that spans an entire system bandwidth of the downlink signal.

23. The radio access node (14) of claim 19 wherein the extra-standard data is at time-frequency locations within the downlink signal that corresponded to muted Channel State Information Reference Signal, CSI-RS, resources.

24. The radio access node (14) of claim 19 wherein the extra-standard data is in symbol periods that are inactive within a subframe structure used for the downlink signal.

25. The radio access node (14) of claim 18 wherein:

in order to receive the signal, the circuitry (24, 58) is further adapted to receive a combined uplink signal comprising the uplink signal and the auxiliary uplink signal.

26. The radio access node (14) of claim 25 wherein when the auxiliary uplink signal is combined with the uplink signal, the extra-standard data is at time- frequency locations within the combined uplink signal that overlap with a shared uplink data channel comprised in the uplink signal.

27. The radio access node (14) of claim 25 wherein when the auxiliary uplink signal is combined with the uplink signal, the extra-standard data is at time- frequency locations within the combined uplink signal that overlap with time- frequency locations in the uplink signal that may be used for one or more uplink sounding reference signals.

28. The radio access node (14) of claim 25 wherein when the auxiliary uplink signal is combined with the uplink signal, the extra-standard data is in symbol periods in the combined uplink signal that correspond to inactive symbol periods within a subframe structure used for the uplink signal.

29. The radio access node (14) of any one of claims 18 to 28 wherein, in order to process the signal received via the adaptive antenna system (32), the circuitry (24, 58) is further adapted to extract the extra-standard data from the signal received via the adaptive antenna system (32) and process the extra-standard data.

30. The radio access node (14) of any one of claims 18 to 29 wherein the extra-standard data comprises adaptive antenna system training data.

31 . A radio access node (14) for a wireless communications system (10), comprising:

an obtaining module (66-1 ) operable to obtain a signal comprising extra- standard data;

a transmitting module (66-2) operable to transmit the signal via an adaptive antenna system (32) of the radio access node (14);

a receiving module (66-3) operable to receive the signal via the adaptive antenna system (32) of the radio access node (14); and

a processing module (66-4) operable to process the signal received via the adaptive antenna system (32).