级联正交空时M-TCM编码方法研究

A New Design for Concatenated Space-Time Block Code M-TCM

空时编码是一种用于多发射天线的编码技术。本文研究级联空时编码系统在编码增益、分集增益和传输能量效率的限定下最大化传输速率的问题,提出一种新的级联正交空时多网格编码调制(M-TCM)方法,并给出不同信道衰落条件下的码字设计方法。分析和仿真结果表明,在准静态Rayleigh衰落信道下,以及具有相同的编码状态数和译码复杂度的情况下,相对于现有的级联空时编码方法,本文编码方法在编码增益上仅相差0.4dB,但却可以提高50%左右的传输速率,并且无需对系统的状态数进行限定,即在保证满分集增益的同时又允许网格图中存在并行路径;而与超正交空时编码方法相比,本文方法可以获得大约2.6dB左右的编码增益,且随着编码状态数的增加,性能的改善就越明显。

The space-time coding is a coding technique designed for multiple-transmission antennas. The maximization of the data rate under the constraint of frame error rate and total transmission power is a considerable issue in the concatenated orthogonal space-time coding system. Based on the concatenated orthogonal space- time coding design criterion, this paper proposed an improved concatenated orthogonal space-time multiple trellis coded modulation approach for different Rayleigh fading channel models. The results of simulations and analyses show that the coding gain loss of the modified concatenated orthogonal space-time coding approach differs only 0.4dB from an existing approach, but its data rate enhance by 50 percent; the modified concatenated orthogonal space-time multiple-trellis coded modulation approach produces 2.6dB coding gain over the concatenated super orthogonal space-time coding approach.