Sidelink control channel successive parameter estimation

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive, within a subframe, a plurality of sidelink control channel signals providing scheduling information for a plurality of sidelink shared channel signals that are also received within the subframe. The UE may determine to use one or more of the plurality of sidelink control channel signals as pilot signals for decoding the plurality of sidelink shared channel signals. The UE may decode the plurality of sidelink shared channel signals based at least in part on the plurality of sidelink control channel signals as pilot signals.

BACKGROUND

The following relates generally to wireless communications, and more specifically to sidelink control channel successive parameter estimation.

Wireless communication systems may include or support networks used for vehicle based communications, also referred to as vehicle-to-everything (V2X) networks, vehicle-to-vehicle (V2V) networks, cellular V2X (CV2X) networks, or other similar networks. Vehicle based communication networks may provide always on telematics where UEs, e.g., vehicle UEs (v-UEs), communicate directly to the network (V2N), to pedestrian UEs (V2P), to infrastructure devices (V2I), and to other v-UEs (e.g., via the network and/or directly). The vehicle based communication networks may support a safe, always-connected driving experience by providing intelligent connectivity where traffic signal/timing, real-time traffic and routing, safety alerts to pedestrians/bicyclist, collision avoidance information, etc., are exchanged. In some examples, communications in vehicle based networks may include safety message transmissions (e.g., basic safety message (BSM) transmissions, traffic information message (TIM), etc.).

Vehicle based communications may be transmitted over one or more sidelink channels. For example, a physical sidelink control channel (PSCCH) may carry control information (e.g., a grant) scheduling data communications on a physical sidelink shared channel (PSSCH). The PSCCH and PSSCH communications may include one or more pilot signals (e.g., reference signals) used for channel estimation. For example, some symbols within a subframe for a PSCCH communication may carry data (e.g., control information) and other symbols may carry pilot signals (e.g., demodulation reference signal (DMRS)). The receiving device uses the pilot signals to perform channel estimation and then uses the channel estimation for decoding the control information. Similarly, some symbols within a subframe for a PSSCH communication may carry data (e.g., BSM, TIM, etc.) and other symbols may carry pilot signals (e.g., DMRS). The receiving devices uses the pilot signals to perform channel estimation and then uses the channel estimation for decoding the data. However, such techniques may not exploit the fact that both the PSCCH and PSSCH may be transmitted using the same antenna port and/or that these channels use adjacent frequencies.

During CV2X communications, a UE decodes multiple transmissions which are simultaneously generated by different UEs. Each transmission is allocated a bandwidth, where various transmissions may be separated in frequency. However, in some instances, a transmission within an allocated bandwidth may leak into other bandwidths allocated for other transmissions. Under these conditions, the orthogonality of some transmissions' bandwidth allocations may be lost and leakage from a strong transmission may interfere with a weak transmission.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support sidelink control channel successive parameter estimation. Generally, the described techniques provide for techniques that ensure or otherwise improve wireless communications between a transmitting device and the receiving device within a cellular vehicle-to-everything (CV2X) network. Broadly, aspects of the described techniques may include the receiving device (e.g., a user equipment (UE)) operating in a CV2X network reusing data and/or pilot signals in a physical sidelink control channel (PSCCH) in decoding data signals in a physical sidelink shared channel (PSSCH). For example, the UE may receive sidelink control channel signals (e.g., signals received over a PSCCH) that carry or otherwise convey scheduling information for a plurality of sidelink shared channel signals (e.g., signals received over a PSSCH). The UE may determine to use some or all of the sidelink control channel signals as pilot signals for decoding the some or all of sidelink shared channel signals. Accordingly, the UE may decode some or all of the sidelink shared channel signals using the sidelink control channel signals as pilot signals. In some aspects, the sidelink control channel signals may be encoded sidelink control channel signals. Accordingly, in some aspects, the UE may decode some or all of the sidelink control channel signals and then re-encode those sidelink control channel signals that were successfully decoded, such that the re-encoded sidelink control channel signals may be used as pilot signals. Accordingly, the UE may determine sidelink control channel parameters of the sidelink control channels (e.g., a first set of parameters associated with PSCCH) by comparing the encoded sidelink control channel signals with the re-encoded sidelink control channel signals. The UE may decode the sidelink shared channel signals based, at least in some aspects, on the channel parameters determined based on the comparison.

In some aspects, the described techniques relate to improved methods, systems, devices, and apparatuses that support sidelink shared channel successive leakage cancellation. Generally, the described techniques provide for techniques that ensure or otherwise improve wireless communications between a transmitting device and the receiving device within a CV2X network. Broadly, aspects of the described techniques may include the receiving device (e.g., a UE) operating in a CV2X network determining an interfering signal from a set of CV2X transmissions, where the interfering signal interferes with an additional concurrently received CV2X transmission (e.g., a victim transmission, or a transmission from a victim UE). The receiving UE may perform an interference canceling procedure to cancel at least a portion of the leaking interfering signal from the additional received CV2X transmission. The UE may then decode data signals from the victim UE based on the interference canceling procedure.

A method of wireless communication at a UE is described. The method may include receiving, within a subframe, a set of sidelink control channel signals providing scheduling information for a set of sidelink shared channel signals that are also received within the subframe, determining to use one or more of the set of sidelink control channel signals as pilot signals for decoding the set of sidelink shared channel signals, and decoding the set of sidelink shared channel signals based on the set of sidelink control channel signals as pilot signals.

An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, within a subframe, a set of sidelink control channel signals providing scheduling information for a set of sidelink shared channel signals that are also received within the subframe, determine to use one or more of the set of sidelink control channel signals as pilot signals for decoding the set of sidelink shared channel signals, and decode the set of sidelink shared channel signals based on the set of sidelink control channel signals as pilot signals.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for receiving, within a subframe, a set of sidelink control channel signals providing scheduling information for a set of sidelink shared channel signals that are also received within the subframe, determining to use one or more of the set of sidelink control channel signals as pilot signals for decoding the set of sidelink shared channel signals, and decoding the set of sidelink shared channel signals based on the set of sidelink control channel signals as pilot signals.

A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to receive, within a subframe, a set of sidelink control channel signals providing scheduling information for a set of sidelink shared channel signals that are also received within the subframe, determine to use one or more of the set of sidelink control channel signals as pilot signals for decoding the set of sidelink shared channel signals, and decode the set of sidelink shared channel signals based on the set of sidelink control channel signals as pilot signals.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining to use one or more of the sidelink control channel signals as pilot signals may include operations, features, means, or instructions for determining that a previous attempt to decode at least one of the set of sidelink shared channel signals was unsuccessful.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for decoding one or more of the encoded sidelink control channel signals as one or more decoded sidelink control channel signals, re-encoding, based on the determining, the one or more decoded sidelink control channel signals as one or more re-encoded sidelink control channel signals, and determining a first set of parameters associated with the one or more of sidelink control channels on which the encoded sidelink control channel signals may be received, the first set of parameters determined based on a comparison of the one or more encoded sidelink control channel signals and the one or more re-encoded sidelink control channel signals, where the first set of parameters may be used in the decoding of the set of sidelink shared channel signals.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, decoding the set of sidelink shared channel signals may include operations, features, means, or instructions for refraining from determining a second set of parameters based on sidelink shared channel pilot signals for a set of sidelink shared channels on which the set of sidelink shared channel signals may be received, and using the first set of parameters as estimated channel parameters in decoding the set of sidelink shared channel signals.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, decoding the set of sidelink shared channel signals may include operations, features, means, or instructions for determining a second set of parameters based on sidelink shared channel pilot signals for a set of sidelink shared channels on which the set of sidelink shared channel signals may be received, using the first set of parameters as course channel parameters in a first step of decoding the set of sidelink shared channel signals, and using the second set of parameters in a second step of decoding the set of sidelink shared channel signals.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, decoding the set of sidelink shared channel signals may include operations, features, means, or instructions for determining a second set of parameters based on sidelink shared channel pilot signals for a set of sidelink shared channels on which the set of sidelink shared channel signals may be received, determining jointly estimated channel parameters based on the first set of parameters and the second set of parameters, and using the determined jointly estimated channel parameters in decoding the set of sidelink shared channel signals.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first set of parameters includes at least one of a frequency offset, or a timing offset, or a Doppler spread, or a delay spread, or a noise covariance estimation, or a channel response estimation, or a combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, decoding one or more of the set of encoded sidelink control channel signals as one or more decoded sidelink control channel signals further may include operations, features, means, or instructions for verifying that each of the one or more decoded sidelink control channel signals passes a cyclic redundancy check.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining to use one or more of the sidelink control channel signals as pilot signals may include operations, features, means, or instructions for identifying that at least one of the set of sidelink control channel signals and at least one of the set of sidelink shared channel signals may be transmitted using a same antenna port.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining to use one or more of the sidelink control channel signals as pilot signals may include operations, features, means, or instructions for identifying that at least one of the set of sidelink control channel signals and at least one of the set of sidelink shared channel signals may be transmitted on adjacent frequencies.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of sidelink control channel signals and the set of sidelink shared channel signals may be CV2X signals.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of sidelink control channel signals may be PSCCH signals and the set of sidelink shared channel signals may be PSSCH signals.

A method of wireless communication at a UE is described. The method may include receiving, from a first wireless device and within a subframe, a first set of sidelink control channel signals providing scheduling information for a first set of sidelink shared channel signals that are received within a first set of subcarriers of the subframe, determining that at least one of a second set of sidelink control channel signals or a second set of sidelink shared channel signals is an interfering signal that is received from a second wireless device and within a second set of subcarriers of the subframe but that includes an interfering signal portion within the first set of subcarriers of the subframe, the second set of subcarriers being different from the first set of subcarriers, performing an interference canceling procedure in order to cancel at least a portion of the interfering signal portion on one or more subcarriers in the second set of subcarriers that are within the first set of subcarriers of the subframe, and decoding the first set of sidelink shared channel signals after the interference canceling procedure.

An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, from a first wireless device and within a subframe, a first set of sidelink control channel signals providing scheduling information for a first set of sidelink shared channel signals that are received within a first set of subcarriers of the subframe, determine that at least one of a second set of sidelink control channel signals or a second set of sidelink shared channel signals is an interfering signal that is received from a second wireless device and within a second set of subcarriers of the subframe but that includes an interfering signal portion within the first set of subcarriers of the subframe, the second set of subcarriers being different from the first set of subcarriers, perform an interference canceling procedure in order to cancel at least a portion of the interfering signal portion on one or more subcarriers in the second set of subcarriers that are within the first set of subcarriers of the subframe, and decode the first set of sidelink shared channel signals after the interference canceling procedure.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for receiving, from a first wireless device and within a subframe, a first set of sidelink control channel signals providing scheduling information for a first set of sidelink shared channel signals that are received within a first set of subcarriers of the subframe, determining that at least one of a second set of sidelink control channel signals or a second set of sidelink shared channel signals is an interfering signal that is received from a second wireless device and within a second set of subcarriers of the subframe but that includes an interfering signal portion within the first set of subcarriers of the subframe, the second set of subcarriers being different from the first set of subcarriers, performing an interference canceling procedure in order to cancel at least a portion of the interfering signal portion on one or more subcarriers in the second set of subcarriers that are within the first set of subcarriers of the subframe, and decoding the first set of sidelink shared channel signals after the interference canceling procedure.

A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to receive, from a first wireless device and within a subframe, a first set of sidelink control channel signals providing scheduling information for a first set of sidelink shared channel signals that are received within a first set of subcarriers of the subframe, determine that at least one of a second set of sidelink control channel signals or a second set of sidelink shared channel signals is an interfering signal that is received from a second wireless device and within a second set of subcarriers of the subframe but that includes an interfering signal portion within the first set of subcarriers of the subframe, the second set of subcarriers being different from the first set of subcarriers, perform an interference canceling procedure in order to cancel at least a portion of the interfering signal portion on one or more subcarriers in the second set of subcarriers that are within the first set of subcarriers of the subframe, and decode the first set of sidelink shared channel signals after the interference canceling procedure.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining that at least one of the second set of sidelink control channel signals or the second set of sidelink shared channel signals may be an interfering signal may include operations, features, means, or instructions for decoding the first set of sidelink control channel signals as first decoded sidelink control channel signals and the second set of sidelink control channel signals as second decoded sidelink control channel signals, where the determining may be based on the first decoded sidelink control channel signals and the second decoded sidelink control channel signals.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining that at least one of the second set of sidelink control channel signals or the second set of sidelink shared channel signals may be an interfering signal further may include operations, features, means, or instructions for identifying that the interfering signal portion of the one or more subcarriers in the second set of sidelink control channel signals or second set of sidelink shared channel signals exceeds a predetermined signal strength threshold within the first set of subcarriers associated with the first plurality of sidelink shared channel signals.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining that at least one of the second set of sidelink control channel signals or the second set of sidelink shared channel signals may be an interfering signal further may include operations, features, means, or instructions for identifying that the first plurality of sidelink shared channel signals received within the first set of subcarriers and the second plurality of sidelink control channel signals or the second plurality of sidelink shared channel signals received within the second set of subcarriers may be within a threshold frequency offset of each other.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining that at least one of the second set of sidelink control channel signals or the second set of sidelink shared channel signals may be an interfering signal further may include operations, features, means, or instructions for identifying that the first plurality of sidelink shared channel signals received within the first set of subcarriers and the second plurality of sidelink control channel signals or the second plurality of sidelink shared channel signals received within the second set of subcarriers may be adjacent to each other.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining that at least one of the second set of sidelink control channel signals or the second set of sidelink shared channel signals may be an interfering signal further may include operations, features, means, or instructions for identifying relative frequency domain positions of the first plurality of sidelink shared channel signals received within the first set of subcarriers and the second plurality of sidelink control channel signals or the second plurality of sidelink shared channel signals received within the second set of subcarriers.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining that at least one of the second set of sidelink control channel signals or the second set of sidelink shared channel signals may be an interfering signal further may include operations, features, means, or instructions for identifying at least one of a modulation and coding scheme, a retransmission policy, or an allocation size and position of the first set of sidelink shared channel signals from the first decoded sidelink control channel signals, and determining that the first set of sidelink shared channel signals may be subject to interference by the at least one of the second set of sidelink control channel signals or second set of sidelink shared channel signals based on the modulation and coding scheme, the retransmission policy, or the allocation size and position of the first set of sidelink shared channel signals.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, determining that at least one of the second set of sidelink control channel signals or the second set of sidelink shared channel signals may be an interfering signal further may include operations, features, means, or instructions for determining at least one of an estimated received power, an estimated signal-to-noise ratio, or an estimated frequency offset of the first set of sidelink shared channel signals based on a corresponding measured received power, a corresponding measured signal-to-noise ratio, or a corresponding measured frequency offset of the first decoded sidelink control channel signals, and determining that the first set of sidelink shared channel signals may be subject to interference by the at least one of the second set of sidelink control channel signals or second set of sidelink shared channel signals based on the estimated received power, the estimated signal-to-noise ratio, or the estimated frequency offset of the first set of sidelink shared channel signals.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, decoding the first set of sidelink control channel signals and the second set of sidelink control channel signals may include operations, features, means, or instructions for verifying that each of the first set of sidelink control channel signals and the second set of sidelink control channel signals passes a cyclic redundancy check.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, performing the interference canceling procedure may include operations, features, means, or instructions for re-encoding the interfering signal, where the interference canceling procedure uses the re-encoded interfering signal to cancel at least the portion of the interfering signal portion within the first set of subcarriers of the subframe.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, performing the interference canceling procedure may include operations, features, means, or instructions for canceling at least a portion of frequency leakage in the first plurality of sidelink shared channel signals received within the first set of subcarriers of the subframe from at least one of the second set of sidelink control channel signals or the second set of sidelink shared channel signals.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying that the interfering signal may be a compound of the at least one of the second set of sidelink control channel signals or second set of sidelink shared channel signals and at least one of a synchronization signal, a feedback signal, or a channel state information reference signal.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of first sidelink control channel signals, the set of first sidelink shared channel signals, the set of second sidelink control channel signals, and the set of second sidelink shared channel signals are CV2X signals.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first set of sidelink control channel signals and the second set of sidelink control channel signals may be physical sidelink control channel (PSCCH) signals and the first set of sidelink shared channel signals and the second set of sidelink shared channel signals may be physical sidelink shared channel (PSSCH) signals.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the wireless communication occurs on a mmW system or a sub-6 GHz system.

DETAILED DESCRIPTION

A wireless multiple-access communications system may include a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). Some wireless networks may support vehicle based communications, such as vehicle-to-everything (V2X) networks, vehicle-to-vehicle (V2V) networks, cellular V2X (CV2X) networks, or other similar networks. Vehicle based communication networks may provide always on telematics where UEs, e.g., vehicle UEs (v-UEs), communicate directly to the network (V2N), to pedestrian UEs (V2P), to infrastructure devices (V2I), and to other v-UEs (e.g., via the network and/or directly). Communications within a vehicle based network may be performed using signals communicated over sidelink channels, such as a physical sidelink control channel (PSCCH) and/or a physical sidelink shared channel (PSSCH). For example, PSCCH may carry control information (e.g., a grant) scheduling data communications on a PSSCH. Typically, each sidelink channel may be used to transmit information as well as pilot signals (such as a demodulation reference signal (DMRS)). The pilot signals may be used to decode the information communicated on the corresponding channel. However, such techniques may not take advantage of the nature of communications within a CV2X network.

In V2V networks, a UE may receive transmissions from multiple UEs. Receiving transmissions from multiple UEs requires different receive power and different frequency offset between the various transmissions. Since a PSCCH signal is more robust than a PSSCH signal, the PSCCH signal is more likely to pass an error check in the presence of leakage from interfering transmissions with adjacent frequency allocations, while the PSSCH may not. In addition, the nature of communications within a CV2X network may allow for additional uses of a PSCCH signal. For example, because both a PSCCH and a PSSCH signal may be transmitted using the same antenna port and with adjacent frequencies, the ratio of received power as well as the frequency offset between the PSCCH signals of two different allocations can be used as a good prediction for the ratio of their corresponding PSSCH signals. Additionally, aspects of the described techniques may take advantage of the fact that the estimated channel parameters of a PSCCH signal are likely similar to the estimated channel parameters of a corresponding PSSCH signal, which means that the channel parameter estimation during the PSSCH decoding stage may make use of the channel estimations of the PSCCH decoding stage. This may lead to techniques for dynamically reducing the leakage of an interfering transmission.

Aspects of the disclosure are initially described in the context of a wireless communications system, such as a vehicle based wireless network. Aspects of the disclosure provide for a receiving device (e.g., a UE operating in a CV2X network) to use PSCCH signal(s) for channel estimation(s) in decoding PSSCH signal(s). For example, the UE may, within a subframe, receive PSCCH signal(s) scheduling information for PSSCH signal(s). The UE may determine to use at least one of the PSCCH signal(s) as pilot signals for decoding the PSSCH signal(s), and therefore decode the PSSCH signal(s) based, at least in some aspects, on the PSCCH signal(s). For example, the PSCCH signal(s) may be encoded PSCCH signal(s). The UE may identify which of the PSCCH signal(s) have been decoded (e.g., cyclic redundancy check (CRC) has passed successfully), and re-encode the decoded PSCCH signal(s). The UE may determine the channel parameters (e.g., the first set of parameters associated with PSCCH) for the re-encoded PSCCH signal(s) by comparing the original (e.g., the encoded) PSCCH signal(s) with the re-encoded PSCCH signal(s). Based on this comparison, the UE may decode the PSSCH signal(s). That is, the UE may use the first set of parameters of the re-encoded PSCCH signal(s) in decoding the PSSCH signal(s).

Aspects of the disclosure are initially described in the context of a wireless communications system. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to sidelink control channel successive parameter estimation.

In some aspects, a UE115may receive, within a subframe, a plurality of sidelink control channel signals providing scheduling information for a plurality of sidelink shared channel signals that are also received within the subframe. The UE115may determine to use one or more of the plurality of sidelink control channel signals as pilot signals for decoding the plurality of sidelink shared channel signals. The UE115may decode the plurality of sidelink shared channel signals based at least in part on the plurality of sidelink control channel signals as pilot signals.

In some aspects, a UE115may receive, within a subframe, a plurality of sidelink control channel signals providing scheduling information for a plurality of sidelink shared channel signals that are also received within the subframe. The UE115may determine that at least one of a plurality of sidelink control channel signals or sidelink shared channel signals is an interfering signal. Upon determining the interfering signal(s), the UE115may perform an interference canceling procedure to cancel at least a portion of the interfering signal. In particular, the portion of the interfering signal that overlaps into a bandwidth allocated for a victim signal is canceled or otherwise mitigated. The UE115may then decode another plurality of sidelink control channel signals received in the bandwidth in which the portion of the interfering signal was canceled, after the interference canceling procedure.

FIG.2illustrates an example of a wireless communication system200that supports sidelink control channel successive parameter estimation in accordance with aspects of the present disclosure. In some examples, wireless communication system200may implement aspects of wireless communication system100. Aspects of wireless communication system200may be implemented by a base station205, a vehicle210, a vehicle215, a vehicle220, a traffic light225, a traffic light230, a traffic light235, and/or a traffic light240. In some aspects, one or more of the traffic lights225-240may be examples of roadside units (RSUs) communicating in wireless communication system200.

In some aspects, wireless communication system200may support vehicle safety and operational management, such as a CV2X network. Accordingly, one or more of the vehicles210-220and/or traffic lights225-240may be considered as UEs within the context of the CV2X network. For example, one or more of the vehicles210-220and/or traffic lights225-240may be equipped or otherwise configured to operate as a UE performing wireless communications over the CV2X network. In some aspects, the CV2X communications may be performed directly between base station205and one or more of the vehicles210-220and/or traffic lights225-240, or indirectly via one or more hops. For example, vehicle215may communicate with base station205via one hop through vehicle210, traffic light240, or any other number/configuration of hop(s). In some aspects, the CV2X communications may include communicating control signals (e.g., one or more PSCCH signals) and data signals (e.g., one or more PSSCH signals).

In some aspects, each UE of wireless communication system200(e.g., vehicles210-220and/or traffic lights225-240) may be configured with a resource allocation for performing CV2X communications. For example, each UE may be configured with a set of frequencies or subcarriers that are allocated for monitoring and receiving control signals (e.g., both data signals and pilot signals received over a PSCCH) within a subframe. In some aspects, each UE may also be configured with the set of frequencies or subcarriers that are allocated for monitoring and receiving data signals (e.g., both data signals and pilot signals received over a PSSCH) within the subframe.

According to some techniques, receiving CV2X communications may be performed by decoding the PSCCH signals first and, based on the decoded PSCCH signals, decoding the PSSCH signals next. In some aspects, V2V communications may be one of the main CV2X applications. In the V2V context, reception may be high speed with a low signal-to-noise ratio (SNR) being required. In these conditions, the accuracy of the channel parameters estimation (e.g., timing offset, frequency offset, channel response, noise power, delay spread, Doppler spread, etc.) may be expected to be low, which may dictate the overall reception performance.

For example, with respect to the PSSCH reception, the transmission of PSCCH signals within the CV2X network may have certain advantages. Some advantages may include signal robustness. For example, the PSSCH signal coding rate may be low (e.g., 0.1) and transmitted using a quadrature phase shift keying (QPSK) constellation. Another example may include the PSSCH signal coding rate being variable (e.g., may reach close to one) and being transmitted using a 64 quadrature amplitude modulated (QAM) constellation. Since CV2X communications may not use channel state information (CSI) feedback, the PSSCH transmission parameters may not be optimized according to fading channel conditions. Another advantage may include power boosting where the PSCCH energy spectral density may be higher than the PSSCH energy spectral density, e.g., 3 dB higher. As discussed, some techniques for PSCCH signal decoding may use the dedicated PSCCH signals for channel estimation. If the PSCCH signal was successfully detected and correctly decoded (e.g., the CRC passed), the PSSCH signal decoding is attempted using the dedicated PSSCH pilot signals for parameter estimation. However, such techniques do not take advantage of the nature and/or configuration of CV2X network communications.

Moreover, such techniques may not take advantage of the fact that both the control and the shared channels (e.g., PSCCH and PSSCH) may be transmitted using the same antenna port and/or that these channels are transmitted using adjacent frequencies (in most scenarios). Under these conditions, aspects of the described techniques may take advantage of the fact that the estimated channel parameters should be similar, which means that the channel parameter estimation during the PSSCH decoding stage may make use of the channel estimations of the PSCCH decoding stage.

In addition, since PSSCH signal decoding is attempted if PSCCH signal decoding is successful (e.g., CRC passes), the PSCCH signals can be re-encoded and used entirely (e.g., both data and pilot signals) as pilot signals for re-estimation of the channel parameters (e.g., a first set of parameters associated with PSCCH) prior to the PSSCH decoding attempt. Aspects of the described techniques may include a variety of options for using the PSCCH channel parameter (e.g., the first set of parameters) estimation during the PSSCH signal decoding stage. In some aspects, these options may correspond to different trade-offs for channel parameter estimation quality vs. complexity. A first option may include using the PSCCH estimated channel parameters (e.g., the first set of parameters) directly (e.g., lowest quality, lowest complexity) in PSSCH decoding. A second option may include using the PSCCH estimated channel parameters (e.g., the first set of parameters) as a course estimation, which is refined using PSSCH pilot signals-based estimations (e.g., a second set of parameters associated with PSSCH) for PSSCH decoding (medium quality, medium complexity). A third option may include using PSCCH and PSSCH pilot signals jointly for channel parameter estimation (e.g., both the first and second sets of parameters associated with PSCCH and PSSCH, respectively) during PSSCH decoding (highest quality, highest complexity). Examples of the parameters in the first and/or second sets of parameters include, but are not limited to, a frequency offset, a timing offset, a Doppler spread, a delay spread, a noise covariance estimation, and/or a channel response estimation.

In some aspects, implementing the described techniques may result in certain gains. One example may include a multiple of three (×3) processing gain, e.g., as there may be up to eight data symbols on top of the four pilot symbols within a subframe. Another gain may be up to a 3 dB processing gain of energy spectral density as compared to PSSCH. Another gain may include up to ×3 granularity in the time domain, e.g., which may better handle high-speed scenarios. In some scenarios, the PSSCH part of an allocation for a UE (which may have a flexible size in the frequency domain) may partially overlap with the PSCCH allocation, with the control part having a lower probability of collision.

Accordingly, aspects of the described techniques may include one or more of the UEs of wireless communication system200(e.g., vehicles210-220and/or traffic lights225-240) receiving, within a subframe, a plurality of PSCCH signals that provide or otherwise convey scheduling information (e.g., grants) for a plurality of PSSCH signals within the subframe.

In some aspects, the UE may determine to use one or more of the PSCCH signals as pilot signals for decoding the plurality of PSSCH signals. In some aspects, the UE may determine to use one or more of the PSCCH signals as pilot signals based on selecting one or more of the trade-offs discussed above, e.g., by selecting a corresponding quality/complexity metric to implement for the CV2X communications. In some aspects, the UE may determine to use one or more of the PSCCH signals as pilot signals based on a previous failed decoding attempt. For example, the UE may determine to use one or more of the PSCCH signals as pilot signals based on a previous attempt to decode at least one of the PSSCH signals being unsuccessful. In some aspects, the UE may determine to use one or more of the PSCCH signals as pilot signals based on determining that the PSCCH signals and the PSSCH signals are transmitted using the same antenna port and/or on adjacent frequencies/subcarriers.

In some aspects, this may include the UE decoding the encoded PSCCH signals. As discussed, a PSCCH signal may be decoded upon passage of the CRC. Based on the determination to use the PSCCH signals as pilot signals and decoding the PSCCH signals, the UE may re-encode the decoded PSCCH signals. The UE may compare the encoded PSCCH signals with the re-encoded PSCCH signals to determine the channel parameters (e.g., the first set of parameters, which may also be referred to as channel parameter estimation, parameters estimation, etc.) to use in decoding the PSSCH signals.

The first option for using PSCCH channel parameter estimation (e.g., the first set of parameters) during the PSSCH signal decoding stage may include the UE refraining from determining channel parameters based on the PSSCH signals (e.g., the second set of parameters) and, instead, using the channel parameters of the PSCCH signals in decoding the PSSCH signals. The second option for using PSCCH channel parameter estimation during the PSSCH signal decoding stage may include the UE determining the channel parameters for the PSSCH pilot signals (e.g., the second set of parameters). The UE may use the channel parameters for the PSCCH signals as course channel parameters in the first step of decoding the PSSCH signals and then use the channel parameters for the PSSCH pilot signals (e.g., the second set of parameters) in the next step of decoding the PSSCH signals.

The third option for using PSCCH channel parameter estimation during the PSSCH signal decoding stage may include the UE determining channel parameters for the PSSCH pilot signals (e.g., the second set of parameters associated with PSSCH). For example, the UE may determine jointly estimated channel parameters based on the channel parameters of the PSCCH signals (e.g., the first set of parameters) and the channel parameters of the PSSCH pilot signals. The UE may use the jointly estimated channel parameters in decoding the PSSCH signals. Accordingly, the UE may leverage the channel parameters determined based, at least in some aspects, on the PSCCH signals (both data or information signals and/or pilot signals) in decoding the PSSCH signals within the subframe.

Thus, the UE may dynamically decide, for each PSSCH allocation, how to use the PSCCH channel parameters in decoding PSSCH signals. In some aspects, this may include the UE attempting to decode all possible PSCCH signals using PSCCH pilot signals for channel parameter estimation. For each correctly decoded PSCCH signal (e.g., CRC passes), the UE may attempt to decode the PSSCH allocation using PSSCH pilot signals for channel parameter estimation. For some or all of the failed PSSCH signal decoding attempts (e.g., CRC fails), the UE may re-encode the PSCCH signals (e.g., use the entire PSCCH signal as pilot signals), estimate the channel parameters (e.g., selecting one of the three estimation options according to the most appropriate quality versus complexity trade-off), and then decode PSSCH signals using the channel parameters determined based on the re-encoded PSCCH signals.

Accordingly, aspects of the described techniques may improve overall reception quality and provide an intelligent balance of receiver complexity. For example, aspects of the described techniques may reduce complexity (e.g. when not required) for the reception of some PSSCH signal allocations, while increasing the complexity for other PSSCH signal allocations in the situation where PSSCH signal decoding is less likely to be successful.

FIG.3illustrates an example of a CV2X subframe300that supports sidelink control channel successive parameter estimation in accordance with aspects of the present disclosure. In some examples, CV2X subframe300may implement aspects of wireless communication systems100and/or200. Aspects of CV2X subframe305may be implemented by a UE, which may be an example of the corresponding devices described herein.

Generally, aspects of CV2X subframe305may be implemented in a wireless multiple-access communications system, such as a CV2X network. For example, the CV2X network may include one or more UEs (with two UEs being shown by way of example only) being configured with an allocation of resources for performing CV2X communications. In some aspects, the configured resources may include a plurality of PSSCH data signals310and PSSCH pilot signals315(e.g., DMRS) as well as a plurality of PSCCH data signals320(e.g., control signals) and PSCCH pilot signals325(e.g., DMRS). In some aspects, each UE may have a corresponding allocation of such resources during some or all of the symbols of CV2X subframe305(with CV2X subframe305shown with 14 symbols by way of example only). In some aspects, CV2X subframe305may include one or more gaps330, with one gap330being shown by way of example only.

As discussed, UEs operating within a CV2X network may be configured with resources to use for performing the vehicle based wireless communications. For example, a first UE (e.g., UE #n) may be configured with a first allocation335and a second UE (e.g., UE #n-1) may be configured with a second allocation340. Generally, each of the first allocation335and/or the second allocation340may include a number of subcarriers used for communicating control information (with 24 PSCCH subcarriers being shown by way of example only) as well as a number of subcarriers used for communicating data information (e.g., with Ma subcarriers being shown by way of example only). In some aspects, the PSCCH subcarriers and the PSSCH subcarriers may be adjacent with respect to each other. In some aspects, the signals transmitted over the PSCCH subcarriers and the PSSCH subcarriers may be transmitted using a common antenna port.

In some aspects, a UE may receive, within CV2X subframe305, a plurality of PSCCH data signals320(which may include a corresponding PSCCH pilot signals325) that schedule information for the plurality of PSSCH data signals310. In some aspects, the UE may determine to use one or more of the plurality of PSCCH data signal320as pilot signals for decoding the plurality of PSSCH data signals310. For example, the UE may make this determination based on the PSCCH and PSSCH signals being communicated using the same antenna port, over adjacent frequencies/subcarriers, and the like. In some aspects, the UE may make this determination based on the trade-off between complexity and quality. In some aspects, the UE may make this determination based on a previously unsuccessful attempt to decode some or all of the PSSCH data signals310.

Accordingly, in some aspects the UE may use the PSCCH pilot signals325to determine channel parameters (e.g., the first set of parameters) used to decode the corresponding PSCCH data signals320. In some aspects, the PSCCH data signals320may be considered decoded upon CRC passage. Based on the determination to use the PSCCH data signal320as pilot signals in decoding the PSSCH data signals310, the UE may re-encode some or all of the decoded PSCCH data signals320. The UE may compare the originally encoded PSCCH signals with the re-encoded PSCCH signals to determine or otherwise derive channel parameters (e.g., the first set of parameters) used for decoding the PSSCH data signals310. For example, the UE may leverage the information obtained from the successfully decoded PSCCH signals in re-encoding the PSCCH signals to determine the channel parameters for the PSCCH data signals320.

In some aspects, the UE may decode some or all of the PSSCH data signals310using the channel parameters determined based on the comparison of the encoded PSCCH signals and the re-encoded PSCCH signals. The UE may use one of the three options discussed above in decoding the PSSCH data signals310. For example, the first option may include the UE refraining from determining the channel parameters for the PSSCH using the PSSCH pilot signals315. Instead, the UE may use the channel parameters determined based on the comparison between the encoded PSCCH signals and the re-encoded PSCCH signals in decoding the PSSCH data signals310.

In the second option, the UE may use the channel parameters determined based on the comparison between the encoded PSCCH signals and the re-encoded PSCCH signals as course channel parameters in a first step of decoding the PSSCH data signals310. The UE may determine the channel parameters for the PSSCH based on the PSSCH pilot signals315, and use these channel parameters as fine channel parameters in the next step of decoding the PSSCH data signals310. In the third option, the UE may use both the channel parameters determined based on the comparison between the encoded PSCCH signals and the re-encoded PSCCH signals as well as the channel parameters for the PSSCH using the PSSCH pilot signals315in decoding the PSSCH data signals310(e.g., both the first and second sets of parameters associated with PSCCH and PSSCH, respectively).

Accordingly, the described techniques may support re-encoding the control channel (e.g., the PSCCH data signals320) and using this to improve reception of the shared channel (e.g., the PSSCH data signals310). Aspects of the described techniques may allow for improved reception of the PSSCH data signal310, provide a mechanism to balance between complexity and quality, and the like.

In some aspects, a UE may receive, within CV2X subframe305a plurality of PSCCH signals from UE #nand a plurality of PSCCH and/or PSSCH signals from UE #n-1. The UE may determine that at least one of the plurality of PSCCH and/or PSSCH signals from UE #n-1comprises an interfering signal with respect to the PSSCH signal from UE #n. Based on identifying the interfering signal, the UE may cancel at least a portion of the interfering signal that is within a bandwidth allocated for the PSSCH signals from UE #n, and then decode PSSCH signals from UE #n. Aspects of the described techniques may allow for improved reception of the PSSCH data signal310.

FIG.4illustrates an example of a process400that supports sidelink control channel successive parameter estimation in accordance with aspects of the present disclosure. In some examples, process400may implement aspects of wireless communication systems100and/or200and/or CV2X subframe300. Aspects of process400may be implemented by a first UE405and/or a second UE410, which may be examples of corresponding devices described herein.

The features of process400are generally described as being performed by the first UE405. However, it is to be understood that these features may be implemented by the second UE410and/or by any other UE, node, device, and the like, operating in a CV2X network. For example, the features of process400may be implemented by a roadside unit (RSU), a vulnerable road user (VRU), a base station, and the like, performing wireless communications within a CV2X network.

At415, the first UE405may receive, within a subframe, a plurality of sidelink control channel signals (e.g., PSCCH signals) that carry or convey scheduling information for a plurality of sidelink shared channel signals (e.g., PSSCH signals) that are also received within the subframe. For example, the first UE405may receive the plurality of sidelink control channel signals from the second UE410and/or from any of the UEs, nodes, devices, etc., operating within the CV2X network.

In some aspects, the plurality of sidelink control channel signals and/or the plurality of sidelink shared channel signals may be CV2X signals. For example, the plurality of sidelink control channel signals may be PSCCH signals and the plurality of sidelink shared channel signals may be PSSCH signals.

At420, the first UE405may determine to use one or more of the plurality of sidelink control channel signals as pilot signals for decoding the plurality of sidelink shared channel signals. In some aspects, this may include the first UE405determining that a previous attempt to decode at least one the plurality of sidelink shared channel signals was unsuccessful.

In some aspects, the first UE405may identify that at least one of the plurality of sidelink control channel signals and the at least one of the plurality of sidelink shared channel signals are transmitted using the same antenna port. In some aspects, the first UE405may identify that at least one of the plurality of sidelink control channel signals and at least one of the plurality of sidelink shared channel signals are transmitted on adjacent frequencies.

At425, the first UE405may decode the plurality of sidelink shared channel signals based at least in part on the plurality of sidelink control channel signals as pilot signals.

In some aspects, the plurality of sidelink control channel signals may be encoded sidelink control channel signals. The first UE405may decode one or more of the encoded sidelink control channel signals as one or more decoded sidelink control channel signals. The first UE405may re-encode, based on the determining, the one or more decoded sidelink control channel signals as one or more re-encoded sidelink control channel signals. The first UE405may determine a first set of parameters associated with the one or more sidelink control channels on which the encoded sidelink control channel signals are received. The first set of parameters may be determined based at least in part on a comparison of the one or more encoded sidelink control channel signals and the one or more re-encoded sidelink control channel signals. The first set of parameters may be used in decoding the plurality of sidelink shared channel signals.

In some aspects, the first UE405may refrain from determining a second set of parameters based on sidelink shared channel pilot signals for a plurality of sidelink shared channels on which the plurality of sidelink shared channel signals are received. The first UE405may use the first set of parameters as estimated channel parameters in decoding the plurality of sidelink shared channel signals.

In some aspects, the first UE405may determine a second set of parameters based on sidelink shared channel pilot signals for a plurality of sidelink shared channels on which the plurality of sidelink shared channel signals are received. The first UE405may use the first set of parameters as course channel parameters in a first step of decoding the plurality of sidelink shared channel signals and use the second set of parameters in a second step of decoding the plurality of sidelink shared channel signals. That is, the first UE405may use the second set of parameters as fine channel parameters in the second step of decoding the plurality of sidelink shared channel signals.

In some aspects, the first UE405may determine a second set of parameters based on sidelink shared channel pilot signals for a plurality of sidelink shared channels on which the plurality of sidelink shared channel signals are received. The first UE405may determine jointly estimated channel parameters based at least in part on the first set of parameters and the second set of parameters and use the jointly estimated channel parameters in decoding the plurality of sidelink shared channel signals.

In some aspects, the parameters within the first set of parameters and/or the second set of parameters may include, but are not limited to, a frequency offset, a timing offset, a Doppler spread, a delay spread, a noise covariance estimation, and/or a channel response estimation.

In some aspects, decoding one or more of the plurality of encoded sidelink control channel signals as one or more decoded sidelink control channel signals may include verifying that each of the one or more decoded sidelink control channel signals passes a CRC.

The receiver510may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to sidelink control channel successive parameter estimation, etc.). Information may be passed on to other components of the device505. The receiver510may be an example of aspects of the transceiver820described with reference toFIG.8. The receiver510may utilize a single antenna or a set of antennas.

The communications manager515may receive, within a subframe, a set of sidelink control channel signals providing scheduling information for a set of sidelink shared channel signals that are also received within the subframe, determine to use one or more of the set of sidelink control channel signals as pilot signals for decoding the set of sidelink shared channel signals, and decode the set of sidelink shared channel signals based on the set of sidelink control channel signals as pilot signals. The communications manager515may be an example of aspects of the communications manager810described herein.

The communications manager515may receive, from a first wireless device and within a subframe, a first set of sidelink control channel signals providing scheduling information for a first set of sidelink shared channel signals that are received within a first set of subcarriers of the subframe, determine that at least one of a second set of sidelink control channel signals or a second set of sidelink shared channel signals is an interfering signal that is received from a second wireless device and within a second set of subcarriers of the subframe but that includes an interfering signal portion within the first set of subcarriers of the subframe, the second set of subcarriers being different from the first set of subcarriers, perform an interference canceling procedure in order to cancel at least a portion of the interfering signal portion on one or more subcarriers in the second set of subcarriers that are within the first set of subcarriers of the subframe, and decode the first set of sidelink shared channel signals after the interference canceling procedure. The communications manager515may be an example of aspects of the communications manager810/1415described herein.

The communications manager615may be an example of aspects of the communications manager515as described herein. The communications manager615may include a sidelink signal scheduling manager620, a pilot signal manager625, and a sidelink signal decoding manager630. The communications manager615may be an example of aspects of the communications manager810described herein.

The sidelink signal scheduling manager620may receive, within a subframe, a set of sidelink control channel signals providing scheduling information for a set of sidelink shared channel signals that are also received within the subframe.

The pilot signal manager625may determine to use one or more of the set of sidelink control channel signals as pilot signals for decoding the set of sidelink shared channel signals.

The sidelink signal decoding manager630may decode the set of sidelink shared channel signals based on the set of sidelink control channel signals as pilot signals.

The transmitter635may transmit signals generated by other components of the device605. In some examples, the transmitter635may be collocated with a receiver610in a transceiver module. For example, the transmitter635may be an example of aspects of the transceiver820described with reference toFIG.8. The transmitter635may utilize a single antenna or a set of antennas.

FIG.7shows a block diagram700of a communications manager705that supports sidelink control channel successive parameter estimation in accordance with aspects of the present disclosure. The communications manager705may be an example of aspects of a communications manager515, a communications manager615, or a communications manager810described herein. The communications manager705may include a sidelink signal scheduling manager710, a pilot signal manager715, a sidelink signal decoding manager720, a decoding attempt manager725, a decoding manager730, an antenna port manager735, and an adjacent frequency manager740. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

The sidelink signal scheduling manager710may receive, within a subframe, a set of sidelink control channel signals providing scheduling information for a set of sidelink shared channel signals that are also received within the subframe. In some cases, the set of sidelink control channel signals and the set of sidelink shared channel signals are CV2X signals. In some cases, the set of sidelink control channel signals are PSCCH signals and the set of sidelink shared channel signals are PSSCH signals.

The pilot signal manager715may determine to use one or more of the set of sidelink control channel signals as pilot signals for decoding the set of sidelink shared channel signals.

The sidelink signal decoding manager720may decode the set of sidelink shared channel signals based on the set of sidelink control channel signals as pilot signals.

The decoding attempt manager725may determine that a previous attempt to decode at least one of the set of sidelink shared channel signals was unsuccessful.

The decoding manager730may decode one or more of the encoded sidelink control channel signals as one or more decoded sidelink control channel signals. In some examples, the decoding manager730may re-encode, based on the determining, the one or more decoded sidelink control channel signals as one or more re-encoded sidelink control channel signals. In some examples, the decoding manager730may determine a first set of parameters associated with the one or more of sidelink control channels on which the encoded sidelink control channel signals are received, the first set of parameters determined based on a comparison of the one or more encoded sidelink control channel signals and the one or more re-encoded sidelink control channel signals, where the first set of parameters are used in the decoding of the set of sidelink shared channel signals.

In some examples, the decoding manager730may refrain from determining a second set of parameters based on sidelink shared channel pilot signals for a set of sidelink shared channels on which the set of sidelink shared channel signals are received. In some examples, the decoding manager730may use the first set of parameters as estimated channel parameters in decoding the set of sidelink shared channel signals. In some examples, the decoding manager730may determine a second set of parameters based on sidelink shared channel pilot signals for a set of sidelink shared channels on which the set of sidelink shared channel signals are received. In some examples, the decoding manager730may use the first set of parameters as course channel parameters in a first step of decoding the set of sidelink shared channel signals. In some examples, the decoding manager730may use the second set of parameters in a second step of decoding the set of sidelink shared channel signals. In some examples, the decoding manager730may determine a second set of parameters based on sidelink shared channel pilot signals for a set of sidelink shared channels on which the set of sidelink shared channel signals are received.

In some examples, the decoding manager730may determine jointly estimated channel parameters based on the first set of parameters and the second set of parameters. In some examples, the decoding manager730may use the determined jointly estimated channel parameters in decoding the set of sidelink shared channel signals. In some examples, the decoding manager730may verify that each of the one or more decoded sidelink control channel signals passes a cyclic redundancy check. In some cases, the first set of parameters and/or the second set of parameters includes at least one of a frequency offset, or a timing offset, or a Doppler spread, or a delay spread, or a noise covariance estimation, or a channel response estimation, or a combination thereof.

The antenna port manager735may identify that at least one of the set of sidelink control channel signals and at least one of the set of sidelink shared channel signals are transmitted using a same antenna port.

The adjacent frequency manager740may identify that at least one of the set of sidelink control channel signals and at least one of the set of sidelink shared channel signals are transmitted on adjacent frequencies.

The communications manager810may receive, within a subframe, a set of sidelink control channel signals providing scheduling information for a set of sidelink shared channel signals that are also received within the subframe, determine to use one or more of the set of sidelink control channel signals as pilot signals for decoding the set of sidelink shared channel signals, and decode the set of sidelink shared channel signals based on the set of sidelink control channel signals as pilot signals.

The communications manager810may receive, from a first wireless device and within a subframe, a first set of sidelink control channel signals providing scheduling information for a first set of sidelink shared channel signals that are received within a first set of subcarriers of the subframe, determine that at least one of a second set of sidelink control channel signals or a second set of sidelink shared channel signals is an interfering signal that is received from a second wireless device and within a second set of subcarriers of the subframe but that includes an interfering signal portion within the first set of subcarriers of the subframe, the second set of subcarriers being different from the first set of subcarriers, perform an interference canceling procedure in order to cancel at least a portion of the interfering signal portion on one or more subcarriers in the second set of subcarriers that are within the first set of subcarriers of the subframe, and decode the first set of sidelink shared channel signals after the interference canceling procedure.

The memory830may include RAM and ROM. The memory830may store computer-readable, computer-executable code835including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory830may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

At905, the UE may receive, within a subframe, a set of sidelink control channel signals providing scheduling information for a set of sidelink shared channel signals that are also received within the subframe. The operations of905may be performed according to the methods described herein. In some examples, aspects of the operations of905may be performed by a sidelink signal scheduling manager as described with reference toFIGS.5through8.

At910, the UE may determine to use one or more of the set of sidelink control channel signals as pilot signals for decoding the set of sidelink shared channel signals. The operations of910may be performed according to the methods described herein. In some examples, aspects of the operations of910may be performed by a pilot signal manager as described with reference toFIGS.5through8.

At915, the UE may decode the set of sidelink shared channel signals based on the set of sidelink control channel signals as pilot signals. The operations of915may be performed according to the methods described herein. In some examples, aspects of the operations of915may be performed by a sidelink signal decoding manager as described with reference toFIGS.5through8.

At1005, the UE may receive, within a subframe, a set of sidelink control channel signals providing scheduling information for a set of sidelink shared channel signals that are also received within the subframe. The operations of1005may be performed according to the methods described herein. In some examples, aspects of the operations of1005may be performed by a sidelink signal scheduling manager as described with reference toFIGS.5through8.

At1010, the UE may determine that a previous attempt to decode at least one of the set of sidelink shared channel signals was unsuccessful. The operations of1010may be performed according to the methods described herein. In some examples, aspects of the operations of1010may be performed by a decoding attempt manager as described with reference toFIGS.5through8.

At1015, the UE may determine to use one or more of the set of sidelink control channel signals as pilot signals for decoding the set of sidelink shared channel signals. The operations of1015may be performed according to the methods described herein. In some examples, aspects of the operations of1015may be performed by a pilot signal manager as described with reference toFIGS.5through8.

At1020, the UE may decode the set of sidelink shared channel signals based on the set of sidelink control channel signals as pilot signals. The operations of1020may be performed according to the methods described herein. In some examples, aspects of the operations of1020may be performed by a sidelink signal decoding manager as described with reference toFIGS.5through8.

At1105, the UE may receive, within a subframe, a set of sidelink control channel signals providing scheduling information for a set of sidelink shared channel signals that are also received within the subframe. The operations of1105may be performed according to the methods described herein. In some examples, aspects of the operations of1105may be performed by a sidelink signal scheduling manager as described with reference toFIGS.5through8.

At1110, the UE may determine to use one or more of the set of sidelink control channel signals as pilot signals for decoding the set of sidelink shared channel signals. The operations of1110may be performed according to the methods described herein. In some examples, aspects of the operations of1110may be performed by a pilot signal manager as described with reference toFIGS.5through8.

At1115, the UE may decode one or more of the encoded sidelink control channel signals as one or more decoded sidelink control channel signals. The operations of1115may be performed according to the methods described herein. In some examples, aspects of the operations of1115may be performed by a decoding manager as described with reference toFIGS.5through8.

At1120, the UE may re-encode, based on the determining, the one or more decoded sidelink control channel signals as one or more re-encoded sidelink control channel signals. The operations of1120may be performed according to the methods described herein. In some examples, aspects of the operations of1120may be performed by a decoding manager as described with reference toFIGS.5through8.

At1125, the UE may determine a first set of parameters associated with the one or more of sidelink control channels on which the encoded sidelink control channel signals are received, the first set of parameters determined based on a comparison of the one or more encoded sidelink control channel signals and the one or more re-encoded sidelink control channel signals, where the first set of parameters are used in the decoding of the set of sidelink shared channel signals. The operations of1125may be performed according to the methods described herein. In some examples, aspects of the operations of1125may be performed by a decoding manager as described with reference toFIGS.5through8.

At1130, the UE may decode the set of sidelink shared channel signals based on the set of sidelink control channel signals as pilot signals. The operations of1130may be performed according to the methods described herein. In some examples, aspects of the operations of1130may be performed by a sidelink signal decoding manager as described with reference toFIGS.5through8.

FIG.12Aillustrates an example of a wireless communication system1200that supports sidelink shared channel successive leakage cancellation in accordance with aspects of the present disclosure. In some examples, wireless communication system1200may implement aspects of wireless communication system100. Aspects of wireless communication system1200may be implemented by a UE115(vehicle) as described with reference toFIG.1.

In some aspects, wireless communication system1200may support vehicle safety and operational management, such as a CV2X network. Accordingly, one or more of the vehicles115may be considered as UEs within the context of the CV2X network. In some aspects, each UE115of wireless communication system1200(e.g., UEs115-a,115-b, and115-c) may be configured with a resource allocation for performing CV2X communications. For example, each UE may be configured with a set of frequencies or subcarriers that are allocated for monitoring and receiving control signals (e.g., PSCCH signals) within a subframe. In some aspects, each UE may also be configured with a set of frequencies or subcarriers that are allocated for monitoring and receiving data signals (e.g., PSSCH signals) within the subframe. In some aspects, wireless communication system1200may operate as a mmW system or a sub-6 GHz system.

According to some techniques, receiving CV2X communications may be performed by decoding the PSCCH signals first and, based on the decoded PSCCH signals, decoding the PSSCH signals next. In some aspects, V2V communications may be one of the main CV2X applications. In V2V conditions, the accuracy of the channel parameters estimation (e.g., timing offset, frequency offset, channel response, noise power, delay spread, Doppler spread, etc.) may dictate the overall reception performance.

For example, wireless communication system1200may include UEs115-a,115-b, and115-cperforming V2V communications with each other. In this example, UE115-amay act as a receiver of V2V signals, with UE115-btransmitting a first signal1205and UE115-ctransmitting an interfering signal1210. Frequency orthogonality between different signals in CV2X communications may hold if there is little or no frequency offset. In other words, if the frequency offset of an interfering signal with respect to the first (or victim) signal is relatively small, the interference from the interfering signal may be negligible. However, if the frequency offset of an interfering signal with respect to the victim signal is relatively large, the interference from the interfering signal may be significant.

In wireless communication system1200, since UE115-cis closer to UE115-athan UE115-b, interfering signal1210may be stronger than first signal1205. If UE115-cis driving toward UE115-awith a high rate of speed, interfering signal1210may have a high frequency offset, which could result in leakage into a bandwidth allocated for reception of the first signal1205. In another example, if UE115-cis driving toward UE115-awith a low rate of speed or is idle, a low frequency offset of interfering signal1210may result with respect to first signal1205.

FIG.12Billustrates examples of frequency domain representations1250and1255in accordance with aspects of the present disclosure. In some examples, frequency domain representations1250and1255may be representative of some aspects of wireless communication systems100and200.

Frequency domain representation1250may be an example where a receiver (e.g., UE115-a) may receive both a first signal1260-a(e.g., first signal1205) and an interfering signal1265-a(e.g., interfering signal1210), where the first signal1260-ais received within a bandwidth that is near that allocated for reception of interfering signal1265-a. In this particular illustration, the frequency offset of the interfering signal1265-awith respect to the first signal1260-ais 200 Hz. Because the frequency offset is relatively small, and because the signal-to-interference plus noise ratio (SINR) for the first signal1260-ais relatively large (with respect to the interfering signal1265-a), the orthogonality between the two signals is preserved. In turn, the receiver may be more likely to successfully receive and decode first signal1260-a(e.g., a target signal) despite the presence of interfering signal1265-a.

Frequency domain representation1255may be an example where a receiver (e.g., UE115-a) may receive both a first signal1260-b(e.g., a target signal, such as first signal1205) and an interfering signal1265-b(e.g., interfering signal1210), where the interfering signal1265-bhas a relatively high frequency offset with respect to the first signal1260-b. In this particular illustration, the frequency offset of interfering signal1265-bwith respect to first signal1260-bis 2500 Hz. Because the frequency offset of interfering signal1265-bis relatively high, and because the SINR of the first signal1260-bis low, the orthogonality between the two signals is not preserved. In turn, the receiver may be less likely to successfully receive and decode first signal1260-b(e.g., the target signal) due to the presence of interfering signal1265-b.

FIG.13illustrates an example of a process1300that supports sidelink shared channel successive leakage cancellation in accordance with aspects of the present disclosure. In some examples, process1300may implement aspects of wireless communication systems100and/or200and/or CV2X subframe300. Aspects of process1300may be implemented by receiving UE115-d, interfering UE115-e, and target UE115-f, which may be examples of corresponding devices described herein. Process400may be performed within a CV2X network.

At1305, receiving UE115-dmay receive and decode from target UE115-f, within a subframe, a plurality of sidelink control channel signals (e.g., PSCCH signals) that carry or convey scheduling information for a plurality of sidelink shared channel signals (e.g., PSSCH signals) that are also received within the subframe. Decoding the plurality of sidelink control channel signals from target UE115-fmay involve verifying that each of the plurality of sidelink control channel signals passes a cyclic redundancy check. The plurality of sidelink control channel signals may be received in a first set of subcarriers of the subframe allotted to target UE115-f.

At1310, receiving UE115-dmay receive and decode from interfering UE115-e, within the same subframe as described in1305, a plurality of sidelink control channel signals and/or a plurality of sidelink shared channel signals. Decoding the plurality of sidelink control channel signals from interfering UE115-emay involve verifying that each of the plurality of sidelink control channel signals passes a cyclic redundancy check. The plurality of sidelink control channel signals and plurality of sidelink shared channel signals may be received in a second set of subcarriers of the subframe allotted to interfering UE115-e. The second set of subcarriers may be different than the first set of subcarriers, and at least a portion (e.g., one or more of the subcarriers) of the second set of subcarriers may be an interfering signal portion within the first set of subcarriers. The interfering signal portion may be comprised of either the plurality of sidelink control channel signals or the plurality of sidelink shared channel signals, or both. The interfering signal portion may also be comprised of a compound of either the plurality of sidelink control channel signals or the plurality of sidelink shared channel signals, or both, and at least one of a synchronization signal, a feedback signal, or a channel state information reference signal.

At1315, with the decoded signals from1305and1310, receiving UE115-dmay perform an interference canceling procedure to cancel the interfering signal portion on one or more subcarriers in the second set of subcarriers that are within the first set of subcarriers of the subframe. The interference canceling procedure may utilize various techniques in canceling the interfering signal portion. For example, receiving UE115-dmay identify that the interfering signal portion exceeds a predetermined signal strength threshold within the first set of subcarriers of the subframe. In another case, receiving UE115-dmay identify that the first set of subcarriers and the second set of subcarriers are within a threshold frequency offset of each other. Other techniques that receiving UE115-dmay utilize in identifying the interfering signal portion include identifying that the first set of subcarriers and the second set of subcarriers are adjacent to each other, or identifying relative frequency domain positions of the first set of subcarriers and the second set of subcarriers.

Additionally, in determining the interfering signal portion, receiving UE115-dmay identify at least one of a modulation and coding scheme, a retransmission policy, or an allocation size and position of the plurality of sidelink shared channel signals from target UE115-f, and then determine that the plurality of sidelink shared channel signals from target UE115-fis subject to interference by the plurality of sidelink control channel signals or plurality of sidelink shared channel signals from interfering UE115-ebased at least in part on the determined modulation and coding scheme, the retransmission policy, or the allocation size and position of the plurality of sidelink shared channel signals from target UE115-f.

Also, in determining the interfering signal portion, receiving UE115-dmay determine at least one of an estimated received power, an estimated signal-to-noise ratio, or an estimated frequency offset from the decoded plurality of sidelink shared channel signals from target UE115-f, and then determine that the plurality of sidelink shared channel signals from target UE115-fis subject to interference by the plurality of sidelink control channel signals or plurality of sidelink shared channel signals from interfering UE115-ebased at least in part on the estimated received power, the estimated signal-to-noise ratio, or the estimated frequency offset.

Also at1315, as part of the interference canceling procedure, receiving UE115-dmay re-encode the interfering signal and then use the re-encoded interfering signal to cancel at least the portion of the interfering signal portion on the one or more subcarriers in the second set of subcarriers that are within the first subcarrier of the subframe. The interfering canceling procedure may also comprise receiving UE115-dcanceling at least a portion of frequency leakage from the interfering signal portion in the first set of subcarriers of the subframe.

At1320, after performing the interference canceling procedure, receiving UE115-dmay decode the plurality of sidelink shared channel signals from target UE115-freceived within the subframe on the first set of subcarriers.

FIG.14shows a block diagram1400of a device1405that supports sidelink shared channel successive leakage cancellation in accordance with aspects of the present disclosure. The device1405may be an example of aspects of a device505, or a UE115as described herein. The device1405may include a receiver1410, a communications manager1415, and a transmitter1435. The device1405may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The receiver1410may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to sidelink shared channel successive leakage cancellation, etc.). Information may be passed on to other components of the device1405. The receiver610may be an example of aspects of the transceiver820described with reference toFIG.8. The receiver1410may utilize a single antenna or a set of antennas.

The communications manager1415may be an example of aspects of the communications manager515as described herein. The communications manager1415may include a sidelink channel manager1420, an interference manager1425, and a coding manager1430. The communications manager1415may be an example of aspects of the communications manager810described herein.

The actions performed by filter manager1415as described herein may be implemented to realize one or more potential advantages. One implementation may allow a UE115to mitigate interfering signals. Another implementation may provide improved data throughput and better user experience at the UE115as interference is reduced.

The sidelink channel manager1420may receive, from a first wireless device and within a subframe, a first set of sidelink control channel signals providing scheduling information for a first set of sidelink shared channel signals that are received within a first set of subcarriers of the subframe.

The interference manager1425may determine that at least one of a second set of sidelink control channel signals or a second set of sidelink shared channel signals is an interfering signal that is received from a second wireless device and within a second set of subcarriers of the subframe but that includes an interfering signal portion within the first set of subcarriers of the subframe, the second set of subcarriers being different from the first set of subcarriers and perform an interference canceling procedure in order to cancel at least a portion of the interfering signal portion on one or more subcarriers in the second set of subcarriers that are within the first set of subcarriers of the subframe.

The coding manager1430may decode the first set of sidelink shared channel signals after the interference canceling procedure.

The transmitter1435may transmit signals generated by other components of the device1405. In some examples, the transmitter1435may be collocated with a receiver1410in a transceiver module. For example, the transmitter1435may be an example of aspects of the transceiver820described with reference toFIG.8. The transmitter1435may utilize a single antenna or a set of antennas.

FIG.15shows a block diagram1500of a communications manager1505that supports sidelink shared channel successive leakage cancellation in accordance with aspects of the present disclosure. The communications manager1505may be an example of aspects of a communications manager515, a communications manager615, a communications manager1410, or a communications manager810described herein. The communications manager1505may include a sidelink channel manager1510, an interference manager1515, a coding manager1520, a frequency manager1525, and an error manager1530. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

The sidelink channel manager1510may receive, from a first wireless device and within a subframe, a first set of sidelink control channel signals providing scheduling information for a first set of sidelink shared channel signals that are received within a first set of subcarriers of the subframe.

In some examples, the sidelink channel manager1510may identify at least one of a modulation and coding scheme, a retransmission policy, or an allocation size and position of the first set of sidelink shared channel signals from the first decoded sidelink control channel signals.

In some examples, the sidelink channel manager1510may determine at least one of an estimated received power, an estimated signal-to-noise ratio, or an estimated frequency offset of the first set of sidelink shared channel signals based on a corresponding measured received power, a corresponding measured signal-to-noise ratio, or a corresponding measured frequency offset of the first decoded sidelink control channel signals.

The interference manager1515may determine that at least one of a second set of sidelink control channel signals or a second set of sidelink shared channel signals is an interfering signal that is received from a second wireless device and within a second set of subcarriers of the subframe but that includes an interfering signal portion on one or more subcarriers in the second set of subcarriers within the first set of subcarriers of the subframe, the second set of subcarriers being different from the first set of subcarriers.

In some examples, the interference manager1515may perform an interference canceling procedure in order to cancel at least a portion of the interfering signal portion on one or more subcarriers in the second set of subcarriers that are within the first set of subcarriers of the subframe.

In some examples, the interference manager1515may identify that the interfering signal portion of the one or more subcarriers in the second set of sidelink control channel signals or second set of sidelink shared channel signals exceeds a predetermined signal strength threshold within the first set of subcarrier associated with the first plurality of sidelink shared channel signals.

In some examples, the interference manager1515may determine that the first set of sidelink shared channel signals is subject to interference by the at least one of the second set of sidelink control channel signals or second set of sidelink shared channel signals based on the modulation and coding scheme, the retransmission policy, or the allocation size and position of the first set of sidelink shared channel signals.

In some examples, the interference manager1515may determine that the first set of sidelink shared channel signals is subject to interference by the at least one of the second set of sidelink control channel signals or second set of sidelink shared channel signals based on the estimated received power, the estimated signal-to-noise ratio, or the estimated frequency offset of the first set of sidelink shared channel signals.

In some examples, the interference manager1515may cancel at least a portion of frequency leakage in the first plurality of sidelink channel signals received within the first set of subcarriers of the subframe from at least one of the second set of sidelink control channel signals or the second set of sidelink shared channel signals.

In some examples, the interference manager1515may identify that the interfering signal is a compound of the at least one of the second set of sidelink control channel signals or second set of sidelink shared channel signals and at least one of a synchronization signal, a feedback signal, or a channel state information reference signal.

The coding manager1520may decode the first set of sidelink shared channel signals after the interference canceling procedure.

In some examples, the coding manager1520may decode the first set of sidelink control channel signals as first decoded sidelink control channel signals and the second set of sidelink control channel signals as second decoded sidelink control channel signals, where the determining is based on the first decoded sidelink control channel signals and the second decoded sidelink control channel signals.

In some examples, the coding manager1520may re-encode the interfering signal, where the interference canceling procedure uses the re-encoded interfering signal to cancel at least the portion of the interfering signal portion on one or more subcarriers in the second set of subcarriers that are within the first set of subcarriers of the subframe.

The frequency manager1525may identify that the first plurality of sidelink shared channel signals received within the first set of subcarriers and the second plurality of sidelink control channel signals or the second plurality of sidelink shared channel signals received within the second set of subcarriers are within a threshold frequency offset of each other.

In some examples, the frequency manager1525may identify that the first plurality of sidelink shared channel signals received within the first set of subcarriers and the second plurality of sidelink control channel signals or the second plurality of sidelink shared channel signals received within the second set of subcarriers are adjacent to each other.

In some examples, the frequency manager1525may identify relative frequency domain positions of the first plurality of sidelink shared channel signals that are received within the first set of subcarriers and the second plurality of sidelink control channel signals or the second plurality of sidelink shared channel signals received within the second set of subcarriers.

The error manager1530may verify that each of the first set of sidelink control channel signals and the second set of sidelink control channel signals passes a cyclic redundancy check.

At1605, the UE may receive, from a first wireless device and within a subframe, a first set of sidelink control channel signals providing scheduling information for a first set of sidelink shared channel signals that are received within a first set of subcarriers of the subframe. The operations of1605may be performed according to the methods described herein. In some examples, aspects of the operations of1605may be performed by a sidelink channel manager as described with reference toFIGS.14and15.

At1610, the UE may determine that at least one of a second set of sidelink control channel signals or a second set of sidelink shared channel signals is an interfering signal that is received from a second wireless device and within a second set of subcarriers of the subframe but that includes an interfering signal portion within the first set of subcarriers of the subframe, the second set of subcarriers being different from the first set of subcarriers. The operations of1610may be performed according to the methods described herein. In some examples, aspects of the operations of1610may be performed by an interference manager as described with reference toFIGS.14and15.

At1615, the UE may perform an interference canceling procedure in order to cancel at least a portion of the interfering signal portion on one or more subcarriers in the second set of subcarriers that are within the first set of subcarriers of the subframe. The operations of1615may be performed according to the methods described herein. In some examples, aspects of the operations of1615may be performed by an interference manager as described with reference toFIGS.14and15.

At1620, the UE may decode the first set of sidelink shared channel signals after the interference canceling procedure. The operations of1620may be performed according to the methods described herein. In some examples, aspects of the operations of1620may be performed by a coding manager as described with reference toFIGS.14and15.

At1705, the UE may receive, from a first wireless device and within a subframe, a first set of sidelink control channel signals providing scheduling information for a first set of sidelink shared channel signals that are received within a first set of subcarriers of the subframe. The operations of1705may be performed according to the methods described herein. In some examples, aspects of the operations of1705may be performed by a sidelink channel manager as described with reference toFIGS.14and15.

At1710, the UE may determine that at least one of a second set of sidelink control channel signals or a second set of sidelink shared channel signals is an interfering signal that is received from a second wireless device and within a second set of subcarriers of the subframe but that includes an interfering signal portion within the first set of subcarriers of the subframe, the second set of subcarriers being different from the first set of subcarriers. The operations of1710may be performed according to the methods described herein. In some examples, aspects of the operations of1710may be performed by an interference manager as described with reference toFIGS.14and15.

At1715, the UE may perform an interference canceling procedure in order to cancel at least a portion of the interfering signal portion on one or more subcarriers in the second set of subcarriers that are within the first set of subcarriers of the subframe. The operations of1715may be performed according to the methods described herein. In some examples, aspects of the operations of1715may be performed by an interference manager as described with reference toFIGS.14and15.

At1720, the UE may re-encode the interfering signal, where the interference canceling procedure uses the re-encoded interfering signal to cancel at least the portion of the interfering signal portion on the one or more subcarriers in the second set of subcarriers that are within the first set of subcarriers of the subframe. The operations of1720may be performed according to the methods described herein. In some examples, aspects of the operations of1720may be performed by a coding manager as described with reference toFIGS.14and15.

At1725, the UE may decode the first set of sidelink shared channel signals after the interference canceling procedure. The operations of1725may be performed according to the methods described herein. In some examples, aspects of the operations of1725may be performed by a coding manager as described with reference toFIGS.14and15.