除此之外，針對兩階段雙向中繼無線通訊，我們提出一種中繼點的非同調檢測法。根據此檢測法的雜訊分析，我們讓兩傳送端使用轉動不同角度的MPSK訊號星座圖做相差編碼，並提出了幾種架構，以改善中繼點的錯誤率。先將中繼點判斷兩傳送端訊號的做法改成基地台判斷兩用戶訊號，再將其延伸到更多用戶情形。 ;Massive MIMO systems are popular studies in recent years. Differential encoding scheme is not required to transmit pilot sequence for channel estimation, so it does not cause pilot contamination. A differentially encoded QAM (quadrature amplitude modulation) scheme for uplink massive MIMO was proposed recently which outperforms conventional differential APSK (amplitude-phase shift keying) scheme for 1000 receiver antennas.
In the predecessors′ papers raise and try to resolve some questions about this differential QAM scheme. construct new tables for differentially encoded 16-QAM. compare differential 16-QAM with differential 16-APSK for the same detector, and compare the detector with a conventional detector for the same transmitter. Simulation results show that differential 16-APSK has the best error performance for any number of receiver antennas.
In this letter, we construct new tables for differentially encoded 32-QAM. We compare differential 32-QAM with differential 32-APSK for the same detector, and compare the detector with a conventional detector for the same transmitter. Simulation results show that differential 32-APSK has the best error performance for any number of receiver antennas. and changing the number of points inside and outside for 16-APSK.
In addition, for two-way two-phase relaying wireless communication, we propose a non-coherent detection method for relay points. According to the noise analysis of this detection method, we let the two transmitting end use the MPSK signal constellation diagrams rotating at different angles for phase difference encoding, and propose several architectures to improve the error rate of the relay point. The paper will first change the way the relay point judges the two transmitter signals to the basestation to determine the two user signals, and then extend it to more users.
