差分SC-FDMA系统关键技术研究

This project is intended to research differential single-carrier frequency domain multiple access (SC-FDMA) system in wireless communication environments. By implementing the research on analysis and design of the differential modulation methods, differential frequency domain equalization (FDE) algorithms, differential carrier frequency offset (CFO) detection and compensation algorithms, and the performance compensation methods of differential modulation based on multi-symbol differential sphere detection (MSDSD), some innovation on key technologies in the differential SC-FDMA system can be expected. The specific contents and objectives are: analyzing the performance of several differential modulation methods in single-input single output (SISO) systems and design multi-dimensional differential coding methods in MIMO systems, consequently, the most appropriate differential modulation method under various conditions can be found; proposing joint differential detection and FDE algorithms and decision feedback differential FDE algorithms based on adaptive feedback signal selecting, hereby, acclimatizing the proposed differential methods to the high-speed broadband mobile communication channel environments; analyzing the effects of CFO when different differential FDE algorithms are applied, proposing blind CFO estimation algorithm and applying parallel interference cancellation to compensate for the CFO, therefore, the performance and adaptability of system can be further improved; and attempting MSDSD to compensate for the performance loss of differential system comparing to the coherent system. Through in-depth theoretical analysis, computer simulation and accompanied by the necessary experiments, the proposed algorithms can be applied in practical wireless communication system in the future.

本项目拟深入研究无线通信环境中的差分SC-FDMA系统，通过对差分调制方式的分析与设计、差分频域均衡算法、差分载波频偏检测及补偿算法以及基于多符号差分球形检测的差分性能劣化补偿算法等内容的研究，能够在差分SC-FDMA系统的关键技术方面有所创新。具体研究内容及目标是：在SISO系统中分析不同差分调制方式的性能,在MIMO系统中设计多维差分编码，找到在各种条件下最适宜的差分调制方式；提出联合差分检测频域均衡算法以及基于自适应反馈信号选择的判决反馈差分频域均衡算法，使系统适应高速宽带移动通信信道环境；分析采用不同差分频域均衡算法时载波频偏的影响，设计盲载波频偏检测算法，应用平行干扰消除补偿载波频偏，从而进一步提高系统的性能及适应性；尝试利用多符号差分球形检测来补偿差分系统相对于相关系统的性能劣化。通过深入的理论分析、计算机仿真并辅之以必要的实验，使所提出的算法在将来能应用于实际无线通信系统中。

本项目研究了差分SC-FDMA系统，对其中的差分调制方式的分析与设计、差分频域均衡算法、差分载波频偏检测及补偿算法、差分性能劣化补偿算法及可见光差分SC-FDMA系统等关键技术进行了研究。具体研究内容为：在SISO系统中设计了多种差分调制方式,在MIMO系统中设计了差分酉空时频编码方式，并分别分析了其性能；设计了一个自适应盲均衡接收机结构，并计算出了抽头系数，同时也采用了粒子群优化对线性均衡和判决反馈均衡抽头系数进行了计算；考虑了差分载波频偏检测及补偿算法，同时提出了基于位置信息的多用户性能优化算法；研究了基于多符号差分球形检测的差分性能劣化补偿算法，推导出了判决度量并分析了其性能；研究了可见光差分SC-FDMA系统，并基于FPGA试制出了系统样机。