Random Beam-based Non-orthogonal Multiple Access for Low Latency Downlink MISO Broadcast Channels

摘要

In this paper, we consider downlink multiple-input and single-output broadcast channels and propose random beam-based non-orthogonal multiple access (NOMA) for low latency. There is a transmitter with multiple antennas with its own single-antenna user group, and the transmitter selects and serves some of multiple-antenna users in the user group. For low latency, we consider random beamforming at the transmitter, so the transmitter does not need to find beamforming vectors, and each user only needs to feed about two scalar values back to the transmitter instead of channel information. In our proposed scheme, the transmitter independently finds NOMA users for each beam, so can reduce the computational complexity. The numerical result shows that our proposed random beam-based NOMA increases the sum achievable rate compared to orthogonal multiple access.