Hybrid-Precoders with Quantized Phase Shifters For Millimeter Wave Communications
In this thesis, we consider hybrid precoding and combining for millimeter transmission wave transmission with large antenna arrays point to point. Due to the high cost of RF chains, phases shifters are widely used to implement the RF beamforming. It is shown recently that the optimal unconstrained precoder can be implemented using only phase shifters. We proposed three schemes for implementation of beamforming weights using the phase shifters. These three schemes yield the same performance as optimal full digitally precoder when the phase shifters are of infinite resolution. This is done by implementing each beamforming weight using two phase shifters. However the performance differ upon phase quantization, we analyze the quantization error on the beamforming weight when the phase shifters are quantized for each proposed case. The analysis is done for the case of high resolution, but the results are accurate even for low resolution quantization as experiments have demonstrated. The simulation show that, with a low quantization resolution, the proposed hybrid precoder can achieve a performance close to that of the full digital precoder that has a dedicated RF chain for each antenna.
|Appears in Collections:||Thesis|