Abstract:
A radio node (16) measures one or more reference signals (18) transmitted from antenna elements of a transmit antenna array (14). The radio node (16) determines a subset of coefficients of a channel correlation matrix that characterizes channel correlation between two or more of the antenna elements of the transmit antenna array (14) according to the measurement. This subset includes, for each of one or more antenna element separation distances, a coefficient from which is derivable channel correlation between any of the two or more antenna elements that are separated by that distance. The radio node (16) then transmits the subset of coefficients as channel correlation feedback (20) that parameterizes the channel correlation matrix.
Abstract:
A user equipment (UE) may be configured to perform a random access channel (RACH) procedure with a base station. As part of the RACH procedure, the base station may transmit a contention resolution message to the UE. The UE may receive, from the base station, the contention resolution message. The contention resolution message may indicate at least a beam index corresponding to a beam, such as a transmit beam of the base station. The UE may determine whether the beam index is applicable to the UE. The UE may communicate with the base station through the beam corresponding to the beam index when the beam index is applicable to the UE. For example, the UE may send an acknowledgement message to the base station, and the base station and UE may switch to a beam corresponding to the beam index after communication of the acknowledgement message.
Abstract:
In one aspect of this disclosure, a communication device sends first and second precoding reports to a network node by time multiplexing the first and second precoding reports onto a reporting channel in accordance with a multiplexing ratio. The first and second precoding reports comprise first and second precoding recommendations,respectively, and correspond to the first and second dimensions of an antenna array used for transmitting to the communication device. Among other advantages, multiplexing of the first and second reports enables the communication device to reuse a reporting channel and at least some of the underlying reporting protocols or signaling arrangements to report multi-dimensional precoding information. The corresponding network node uses its knowledge of the multiplexing ratio to differentiate between the first and second reports. Moreover, the involved multiplexing ratio may be adapted, either by the network or the communication device, in view of changing operating scenarios.
Abstract:
RADIO CHANNEL SOUNDING A downstreamsounding packet (201) is transmitted and a downstream channel state (499) of a radio channel is determined based on at least onereceive propertyof the preamble of the downstream sounding packet (209). An upstreampacket (211 –214) is received. The determined downstreamchannel state (499) is reevaluated based on a receive propertyof a preamble of the upstreampacket (211 –214). (FIG. 3A)
Abstract:
본 명세서는, 차량 간 통신 시스템에서 단말이 기지국으로 채널 정보를 송신하는 방법에 대한 것이다. 이때, 채널 정보를 송신하는 방법은 채널 정보를 측정하여 기지국으로 피드백하는 단계 및 채널 정보에 기초하여 데이터를 수신하는 단계를 포함할 수 있다. 이때, 단말이 복수의 분포 안테나(Distributed Antenna Unit, DU)를 포함하고, 복수의 DU 각각에 대한 활성화 여부의 선택이 가능한 경우, 활성화되는 DU 수 및 위치에 따라 복수의 채널 정보 셋(set)이 측정되고, 피드백되는 채널 정보는 상기 복수의 채널 정보 셋들로 구성될 수 있다.
Abstract:
본 발명의 일 실시예에 따른, WLAN(Wireless LAN) 시스템에서 하향링크(DL: Downink) 채널 상태에 관한 피드백 정보를 전송하기 위한 STA(Station)의 사운딩 방법에 있어서, NDP(Null data packet) 프레임의 전송을 알리는 NDPA(NDP announcement) 프레임을 수신하는 단계; 상기 NDP 프레임을 수신하는 단계; 상기 STA에 할당된 자원 할당 정보가 포함된 트리거 프레임을 수신하는 단계; 상기 NDP 프레임에 포함된 트레이닝 필드를 기초로 채널 상태 정보를 생성하는 단계; 및 상기 채널 상태 정보가 포함된 피드백 프레임을 상기 자원 할당 정보가 지시하는 주파수 자원을 이용하여 상향링크(UL: Uplink) 다중 사용자(MU: Multi-User) 전송하는 단계; 를 포함할 수 있다.
Abstract:
In wireless communications, an access point may send a first frame and a second frame to multiple stations. In one aspect, the first frame may be a frame for initiating a sounding protocol. The first frame may include subband-related information. In response to the first and second frames, one or more stations may generate beamforming feedback information based on content of the second frame according to the subband-related information of the first frame. The beamforming feedback information may include average signal-to-noise ratios (SNRs), where an SNR may be for a space-time stream averaged over data subcarriers in a subband. The stations may send a third frame(s) that includes the beamforming feedback information to the access point. The access point may generate, and transmit to the stations, a beamforming matrix based on the third frame(s). Other methods, apparatus, and computer-readable media are also disclosed.