Abstract:
Various solutions for downlink control signal design with respect to user equipment and network apparatus in mobile communications are described. An apparatus may receive a first downlink control signal from a first source. The apparatus may receive a second downlink control signal from a second source. The apparatus may further receive downlink data according to the first downlink control signal and the second downlink control signal. The first downlink control signal and the second downlink control signal may be identical. The first source and the second source may be different.
Abstract:
A user equipment (UE) utilizes a first group of antenna ports at the UE for transmitting and receiving while utilizing a second group of antenna ports for receiving but not transmitting. The UE transmits to a base station (BS) a sounding reference signal (SRS) via the first group of antenna ports through a first channel of a communication link between the UE and the BS. The UE receives from the BS a channel state information reference signal (CSI-RS) via the first and second groups of antenna ports through the first channel and a second channel of the communication link. The UE determines an estimated channel response and a matrix such that a product of the matrix and a channel response of the first channel approximates a channel response of the second channel. The UE transmits to the BS a CSI feedback indicating at least the matrix.
Abstract:
A method of performing downlink multiuser superposition transmission (MUST) with enhanced channel state information (CSI) feedback is proposed. When a user equipment (UE) reports CQI/SINR feedback for RI=RANK-2, the UE also reports a single beam CQI/SINR feedback for RI=RANK1. As a result, the scheduling base station can calculate the actual SINRs based on different MUST scenarios and thereby determining appropriate modulation and coding scheme (MCS) for the UE. Furthermore, if the granularity of the CQI table cannot reflect the high values of the single beam SINR, then a predefined scaling factor (0
Abstract:
Methods for rate matching with soft buffer size setting at the transmitter and soft channel bits storage at the receiver for superposition coding are proposed. In the superposition coding scheme, a transport block intended to one UE needs to be decoded by another UE's receiver. However, the soft buffer sizes per code block of the two receivers may not be the same since the size depends on the UE category. The base station can signal the soft buffer size used at the transmitter for rate matching to the UEs for superposition decoding. A UE stores information bits associated with an interfering signal in its soft buffers in accordance with the soft buffer size used at the transmitter for rate matching. As a result, the UE can decode and subtract the interfering signal from the desired signal for superposition coding.
Abstract:
A method is proposed to enable a UE performing codeword level interference cancellation (CW-IC) to know whether an interfering transport block (TB) is a new transmission or retransmission. With this knowledge, the UE knows whether the soft channel bits stored in a soft buffer are to be discarded or combined with the soft channel bits newly obtained.
Abstract:
A method of modulating and demodulating superposed signals for MUST scheme is proposed. A transmitter takes bit sequences intended for multiple receivers under MUST scheme to go through a “bit sequence to constellation points” mapper before entering the modulators to satisfy the Gray coding rule and to achieve high demodulation performance for the receivers. In a first method, each bit sequence is assigned for each constellation point on the constellation map to satisfy one or more conditions under different power split factors. In a second method, the constellation map is divided into sub-regions according to the clustering of the constellation points for bit sequence assignment. A near-UE may use an ML receiver for demodulation and decoding the superposed signal. A far-UE may use an ML receiver or an MMSE receiver for demodulation and decoding the superposed signal.