摘要
本文针对Turbo编码的多进制正交扩频BDPSK复合调制(NOrth-BDPSK)系统,给出了多进制正交扩频调制的比特软值输出算法的推导过程,提出了基于最大后验概率(MAP)准则的BDPSK解调比特软值输出算法,同时给出了BDPSK解调软值的简化算法,最后进行了仿真评估,并与单纯NOrth调制系统进行比较。结果表明:NOrth-BDPSK能以较低的性能损失为代价提供更高的带宽效率。
Focusing on Turbo-coded joint modulation of N-ary Orthogonal Spread Spectrum and BDPSK, this paper derives the bit soft-output algorithm of N-ary Orthogonal Spread Spectrum demodulation, and proposes the algorithm for computing bit soft metric of BDPSK demodulation based on maximum a posteriori probability （MAP） criterion, meanwhile, the simplified algorithm of BDPSK soft metric is given. Lastly, the system is simulated and compared with the system of N-ary Orthogonal Spread Spectrum modulation. It is shown that the system of NOrth-BDPSK can improve the bandwidth efficiency with little performance cost.
出处
《电路与系统学报》
CSCD
北大核心
2008年第1期23-28,34,共7页
Journal of Circuits and Systems
