提出一种基于比特交织编码调制(BICM)的高效编码协作(CC)方案,该方案中协作用户编码比特分为两帧,每一帧都通过BICM调制发送,通过结合比特交织器满足高阶调制星座符号的不同比特经历的衰落独立.一方面,论文分析了该协作方案在不同信道下的成对错误概率,并进一步推导了错误比特概率上界.理论分析以及仿真结果都表明:准静态衰落信道下,基于BICM的高谱效率编码协作方案仍然可以获得完全分集;而快衰落信道下,编码协作没有分集.另一方面,论文针对提出CC方案中映射方式以及交织器的设计进行研究,得出GRAY映射仍然是协作用户采用的最佳映射,且两帧的交织器不同更利于提高性能.
A high-efficient coded cooperative scheme based on bit-interleaved coded modulation is proposed.Encoded bits of the cooperative user are partitioned into two frames,bit interleaved,mapped and then transmitted on the allocated time slots respectively.Bit interleaver is utilized to satisfy the fading coefficients of the different bits of a same symbol cound be modeled as i.i.d variables.One hand,the pairwire error probability over various fading channels is derived,and an upper-bound on bit-error probability is presented.Both theory analysis and simulations show that the BICM CC with high-order constellations can also achieve the full diversity under quai-static Rayleigh fading channels,whereas no any cooperation diversity over fast fading channels.On the other hand,labeling maps and interleavers are studied.It can be concluded that GRAY labeling is still optimum for the cooperative users and different interleavers of two frames can improve the performance.