A Constant-Gap Result on the Multi-Antenna Broadcast Channels with Linearly Precoded Rate Splitting

Sheng Yang (1) , Zheng Li (1)

1 L2S - Laboratoire des signaux et systèmes

In this paper, we consider a simple downlink channel with a multi-antenna base station and two single-antenna receivers. We assume that the channel is deterministic and known to all the nodes. Our contribution is two-fold. First, we show that linear precoding with private streams can have unbounded gap to the capacity of the channel. Second, we show that using rate-splitting with a simple power allocation one can achieve the sum capacity to within a constant gap for any channel realization.

Domaines: Théorie de l'information [cs.IT]

Sheng Yang, Zheng Li. A Constant-Gap Result on the Multi-Antenna Broadcast Channels with Linearly Precoded Rate Splitting. 19th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC 2018), Jun 2018, Kalamata, Greece. ⟨10.1109/SPAWC.2018.8446000⟩. ⟨hal-01912264⟩