基于OFDM 系统的差分空频时编码

基于OFDM(正交频分复用)系统,提出了一种新的空频时三维编码,将网格编码调制和差分空时分组码进行组合链接设计。在信道状态信息很难获取的情况下,它可以很好地工作在频率选择性信道中。进一步分析并推导了非相干检测下该编码的性能。仿真结果表明,这种新的编码方案可以获得编码增益以及满的空间域和频域分集增益,很好地支持了理论分析。

Differential space-frequency-time code design based on OFDM systems

Based on OFDM system, a novel space-frequency-time code which combined trellis-coded modulation with differential space-time block code was proposed. The differential space-frequency-time code performed effectively over frequency-selective channels in some situations when the accurate channel estimation became very difficult. In addition, the diversity order of the proposed code in the case of noncoherent detection was analyzed and derived. The simulation results show that the code achieves not only the code gain, but also the frequency and spatial domain diversity offered by channel, which approves the theoretical analysis.