基于TCM-OFDM方式的多符号信号检测方法分析

Analysis of Multiple Symbol Detecting Method Based on TCM-OFDM

介绍了一种基于TCM-OFDM方式的多符号信号检测方法。利用π/4 移位的 QPSK网格编码调制技术,通过信号集进行扩展和相位差进行划分,提出了π/8 移位的 8PSK-OFDM技术。在维特比解码代数中,对连续接收到的符号(从第 1 到 L个相位差)可以使用新的分支量度值来解码。这样的滑动多符号检测(Sliding Multiple Symbol Detection ,SMSD)方法使误码率 (BitErro Rate,BER)性能得到了改进,在不损失带宽和功率的前提下可以适用于各种不同的通信信道。因此,笔者提出的调制和滑动检测方案特别适合于功率和带宽受限系统。通过仿真进一步证实了上述理论的可行性。

In this paper, a kind of Multiple Symbol Detecting Method based on TCM-OFDM (Trellis coded modulation-Orthogonal Frequency Division Multiplexing) is introduced. Trellis-coded π/8 shift 8PSK OFDM technique is proposed by applying π/4 shift QPSK to Trellis-coded modulation and performing signal set expansion and set partition correspondingly based on phase difference. In Viterbi decoding algorithm, symbols successively received (phase differences from 1 to L) are employed in the new branch metrics. Such a sliding multiple symbol detection (SMSD) method improved bit-error-rate (BER) performance and can be applied to different communication channels, especially the power and band-limited systems, without sacrificing bandwidth and power efficiency.