串行级连空时编码系统的匹配问题研究

The matching among serially concatenated space-time coding systems

在空时编码系统的设计中,通常是在保证分集增益的前提下优化编码增益.文中提出一种通过内、外码相互匹配来优化串行级连空时编码系统的新方法,详细分析了外码冗余信息对整个串行级连系统的影响,指出利用交织器对外码输出序列的置换作用可达到内外码之间的匹配.该方法可使系统复杂度进一步降低.仿真结果表明,通过匹配方式优化的级连系统比采用现有最优码的系统有2dB增益.

The diversity gain is always maximized first before coding gains are optimized in the design of a spacetime coding system. The similar method is alwasy adopted in designing the serially concatenate spacetime coding system (SCST). A new optimization method for the optimization of SCST via matching the inner and outer encoder is presented. The effect of outer code redundancies on the performance of SCST is analyzed carefully. It is also pointed out that the matches between the inner and outer encoder can be acquired via the permutation of the interleaver on the outputs of the outer encoder. The work in this paper also provides the possibility to decrease the system complexity further. The simulation results show that the matched SCST system obtains approximately 2?dB gains compared with those SCSTs with available STTC in other contributions.