Abstract: Methods, systems, and devices for interleaved mapping are described. In some implementations, a transmitting device identifies a set of virtual resource blocks (VRBs) corresponding to at least one code block to be transmitted to a receiving device. The transmitting device may determine that a quantity of VRBs to be transmitted to the receiving device is different than a quantity of entries within a regular interleaving matrix. Thus, the transmitting device may map each of the VRBs to a physical resource block (PRB) according to an irregular interleaving matrix to generate at least one interleaved code block. The transmitting device may transmit the interleaved code block to the receiving device. The receiving device may receive the interleaved code block and identify the PRBs associated with the interleaved code block. The receiving device may map each PRB within the interleaved code block to a VRB according to an irregular deinterleaving matrix.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may receive configuration information that indicates a transmission parameter associated with a random access response (RAR) type; transmit a random access message associated with the RAR type; use the transmission parameter to obtain a physical downlink control channel (PDCCH) communication that schedules a physical downlink shared channel (PDSCH) communication that includes a RAR in a medium access control protocol data unit of the PDSCH communication; and obtain or refraining from obtaining the PDSCH communication based at least in part on whether the PDCCH communication is successfully obtained using the transmission parameter. Numerous other aspects are provided.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, on a first carrier having a first subcarrier spacing (SCS), a scheduling indication via a physical downlink control channel (PDCCH) scheduling a downlink transmission on a second carrier having a second SCS. The UE may process the downlink transmission on the second carrier based at least in part on a delay between the PDCCH and the scheduled downlink transmission and a timing threshold having a basic term and an adjustment term. For example, the basic term may be based at least in part on a minimum delay between the PDCCH and the scheduled downlink transmission, and the adjustment term may be based at least in part on a processing time due to a difference between the first SCS and the second SCS. Numerous other aspects are provided.

Abstract: Aspects of the present disclosure implement techniques that allow a vehicle performing V2X communications to provide more accurate S-RSSI measurements and CBR calculations for use in channel selection and congestion control. Techniques may include measuring a sidelink received signal strength indicator (S-RSSI) for each of a plurality of sub-channels, determining one or more signal impairment adjustment factors based on the S-RSSI for each of the plurality of sub-channels, calculating a channel busy ratio (CBR) for the plurality of sub-channels based on the one or more signal impairment adjustment factors, and initiating communication with at least one of the plurality of sub-channels based on at least the CBR.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may receive configuration information that indicates a transmission parameter associated with a random access response (RAR) type; transmit a random access message associated with the RAR type; use the transmission parameter to obtain a physical downlink control channel (PDCCH) communication that schedules a physical downlink shared channel (PDSCH) communication that includes a RAR in a medium access control protocol data unit of the PDSCH communication; and obtain or refraining from obtaining the PDSCH communication based at least in part on whether the PDCCH communication is successfully obtained using the transmission parameter. Numerous other aspects are provided.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, on a first carrier having a first subcarrier spacing (SCS), a scheduling indication via a physical downlink control channel (PDCCH) scheduling a downlink transmission on a second carrier having a second SCS. The UE may process the downlink transmission on the second carrier based at least in part on a delay between the PDCCH and the scheduled downlink transmission and a timing threshold having a basic term and an adjustment term. For example, the basic term may be based at least in part on a minimum delay between the PDCCH and the scheduled downlink transmission, and the adjustment term may be based at least in part on a processing time due to a difference between the first SCS and the second SCS. Numerous other aspects are provided.

Abstract: Methods, systems, and devices for interleaved mapping are described. A transmitting device may identify a set of virtual resource blocks (VRBs) corresponding to at least one code block to be transmitted to a receiving device. The transmitting device may determine that a quantity of VRBs to be transmitted to the receiving device is different than a quantity of entries within a regular interleaving matrix. Thus, the transmitting device may map each of the VRBs to a physical resource block (PRB) according to an irregular interleaving matrix to generate at least one interleaved code block. The transmitting device may transmit the interleaved code block to the receiving device. The receiving device may receive the interleaved code block and identify the PRBs associated with the interleaved code block. The receiving device may map each of the PRBs within the interleaved code block to a VRB according to an irregular deinterleaving matrix.

Abstract: Aspects of the present disclosure implement techniques that allow a vehicle performing V2X communications to provide more accurate S-RSSI measurements and CBR calculations for use in channel selection and congestion control. Techniques may include measuring a sidelink received signal strength indicator (S-RSSI) for each of a plurality of sub-channels, determining one or more signal impairment adjustment factors based on the S-RSSI for each of the plurality of sub-channels, calculating a channel busy ratio (CBR) for the plurality of sub-channels based on the one or more signal impairment adjustment factors, and initiating communication with at least one of the plurality of sub-channels based on at least the CBR.

Abstract: Certain aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may receive sidelink control information (SCI) associated with a remote vehicle; identify a threat metric associated with the remote vehicle based at least in part on one or more characteristics of the remote vehicle, wherein the one or more characteristics are determined based at least in part on vehicle information received in one or more transport blocks corresponding to prior SCI associated with the remote vehicle and received prior to the SCI; and process the SCI based at least in part on the threat metric. Numerous other aspects are provided.

Abstract: Channel quality may be measured in a device-to-device (D2D) communication network. The D2D communication network may include one or more D2D wireless transmit/receive units (WTRUs), wherein the D2D WTRUs may communicate using a D2D bandwidth. A D2D WTRU may receive a channel measurement resource configuration corresponding to a channel measurement resource. The D2D WTRU may further receive an RS on the channel measurement resource. The D2D WTRU may measure one or more channel state parameters from the channel measurement resource for a part of bandwidth overlapping with a D2D communication bandwidth, when the RS bandwidth is greater than the D2D communication bandwidth. The D2D WTRU may report the channel state parameters to a controlling entity. The controlling entity may configure a D2D frequency allocation between a transmitting device and a receiving device. The D2D frequency allocation may be based on the time averaged measurement.

Abstract: An iterative nonlinear preceding method based on, for example. Tomlinson-Harashima Preceding (THP) may be implemented in a MU-MIMO system to alleviate the performance degradation due to mismatches between actual Channel State Information (CSI) and impaired CSI available at a transmitter. In such a method, the effective channel may be fed back rather than a nonprecoded channel for a relay backhaul channel such that the iterative precoding and effective channel feedback may reduce the sensitivity to quantization errors and improve spectrum usage efficiency. Additionally, a Channel Quality Indicator (CQI) may be used to estimate a signal-to-interference-plus-noise (SINK) ratio based on quantization errors to accurately derive the effective channel quality of the receiver.

Abstract: Channel quality may be measured in a device-to-device (D2D) communication network. The D2D communication network may include one or more D2D wireless transmit/receive units (WTRUs), wherein the D2D WTRUs may communicate using a D2D bandwidth. A D2D WTRU may receive a channel measurement resource configuration corresponding to a channel measurement resource. The D2D WTRU may further receive an RS on the channel measurement resource. The D2D WTRU may measure one or more channel state parameters from the channel measurement resource for a part of bandwidth overlapping with a D2D communication bandwidth, when the RS bandwidth is greater than the D2D communication bandwidth. The D2D WTRU may report the channel state parameters to a controlling entity. The controlling entity may configure a D2D frequency allocation between a transmitting device and a receiving device. The D2D frequency allocation may be based on the time averaged measurement.

Abstract: A method and apparatus for cross link (XL) establishment are disclosed. In the method and apparatus, a XL between a terminal wireless transmit/receive unit (T-WTRU) and a helper WTRU (H-WTRU) is established. The T-WTRU and the H-WTRU may be configured to operate in a plurality of RRC states and a plurality of RRC substates. To establish the XL, neighbor discovery, association information exchange, and a H-WTRU selection may be performed. Radio resource control (RRC) configuration of the T-WTRU and the H-WTRU may also be performed. In the method and apparatus, coverage for a T-WTRU may be handed over between a network and a H-WTRU or between two H-WTRUs.

Abstract: Channel quality may be measured in a device-to-device (D2D) communication network. The D2D communication network may include one or more D2D wireless transmit/receive units (WTRUs), wherein the D2D WTRUs may communicate using a D2D bandwidth. A D2D WTRU may receive a channel measurement resource configuration corresponding to a channel measurement resource. The D2D WTRU may further receive an RS on the channel measurement resource. The D2D WTRU may measure one or more channel state parameters from the channel measurement resource for a part of bandwidth overlapping with a D2D communication bandwidth, when the RS bandwidth is greater than the D2D communication bandwidth. The D2D WTRU may report the channel state parameters to a controlling entity. The controlling entity may configure a D2D frequency allocation between a transmitting device and a receiving device. The D2D frequency allocation may be based on the time averaged measurement.

Abstract: A method and apparatus for using demodulation reference signal (DM-RS) based channel state information (CSI) feedback in Orthogonal Frequency Division Multiplexing-multiple-input multiple-output (OFDM-MIMO) systems is disclosed. A wireless transmit/receive unit (WTRU) may include: a receiver configured to receive broadcast information from an eNodeB, wherein the broadcast information is received by a plurality of WTRUs; and a processor configured to derive, from the received broadcast information, physical resource blocks having demodulation reference signals (DM-RS) and precoding information of the DM-RS; the receiver and the processor further configured to derive a channel estimation using the DM-RS received in the physical resource blocks, wherein the plurality of WTRUs derive a channel estimation using the DM-RS received in the physical resource blocks.

Abstract: A method and apparatus for using demodulation reference signal (DM-RS) based channel state information (CSI) feedback in Orthogonal Frequency Division Multiplexing-multiple-input multiple-output (OFDM-MIMO) systems is disclosed. The wireless transmit/receive unit (WTRU) receives one or more resource blocks from a base station, wherein the resource blocks (RBs) include demodulating reference signals (DM-RS) and precoder information. The precoder information is sent unicast or broadcasted over a common control channel. The WTRU estimates an effective channel estimate based on the DM-RS, derives an unprecoded channel based on the effective channel and the precoder information, generates CSI feedback based on the unprecoded channel, and transmits the CSI feedback to the base station. Alternatively, the WTRU estimates an effective channel estimate based on the DM-RS, quantizes the effective channel estimate and transmits the CSI feedback to the base station.

Abstract: A method and apparatus for cross link (XL) establishment are disclosed. In the method and apparatus, a XL between a terminal wireless transmit/receive unit (T-WTRU) and a helper WTRU (H-WTRU) is established. The T-WTRU and the H-WTRU may be configured to operate in a plurality of RRC states and a plurality of RRC substates. To establish the XL, neighbor discovery, association information exchange, and a H-WTRU selection may be performed. Radio resource control (RRC) configuration of the T-WTRU and the H-WTRU may also be performed. In the method and apparatus, coverage for a T-WTRU may be handed over between a network and a H-WTRU or between two H-WTRUs.

Abstract: A method and apparatus for using demodulation reference signal (DM-RS) based channel state information (CSI) feedback in Orthogonal Frequency Division Multiplexing-multiple-input multiple-output (OFDM-MIMO) systems is disclosed. The wireless transmit/receive unit (WTRU) receives one or more resource blocks from a base station, wherein the resource blocks (RBs) include demodulating reference signals (DM-RS) and precoder information. The precoder information is sent unicast or broadcasted over a common control channel. The WTRU estimates an effective channel estimate based on the DM-RS, derives an unprecoded channel based on the effective channel and the precoder information, generates CSI feedback based on the unprecoded channel, and transmits the CSI feedback to the base station. Alternatively, the WTRU estimates an effective channel estimate based on the DM-RS, quantizes the effective channel estimate and transmits the CSI feedback to the base station.

Abstract: Systems and methods for channel quality indicator (CQI) feedback may be disclosed. At a current transmission time interval, precoder and/or modulation information that may be used at or associated with a future transmission time interval may be determined. As such, at a current transmission time interval, precoder and/or modulation information that may be used to select a modulation or coding scheme (MCS) and/or schedule transmission at a future transmission time interval may be predicted in the current transmission time interval. The precoder and/or modulation information may be broadcast and received such that the information may be used to estimate a channel quality indicator (CQI) at the current transmission time interval. The estimated CQI may be used to select a modulation and coding scheme (MCS), schedule transmissions, and the like.

Abstract: Disclosed herein are measurement and interference avoidance for direct device-to-device (D2D) links. A method may be implemented by a wireless transmit/receive unit (WTRU). The method may include determining a sounding reference signal (SRS) to detect high interference and facilitate measurements on a link with another WTRU. The method may also include using the SRS on a direct link with another WTRU.