【摘要】 为了提高DMR系统基带算法的性能,分析研究了DMR标准中的3/4率网格码和二次剩余码。针对3/4率网格码,提出两种译码算法,方法 1充分利用了有限状态机的特性,方法 2将维特比译码算法中的蝶形运算进行推广改进。针对QR码,通过计算校验多项式的码重进行译码。MATLAB下的仿真结果表明,3/4率网格码的两种译码方法性能相差不大,但方法一的计算量少,易于工程实现。QR码的译码算法不仅有效地避免了计算复杂的错误位置多项式,而且提高了相同信噪比下的译码性能。更多还原

【Abstract】 For better performance of DMR system,this paper focused on rate 3/4 trellis code and QR(quadratic residue) code in DMR standard.As for the rate 3/4 trellis code,it proposed two different decoding algorithms.One made full use of the characteristics of finite state machine,and the other refined the butterfly computation in viterbi decoding algorithm.It presented a new algorithm to decode QR code by computing the weight of its syndrome polynomial.Simulational results show that the two decoding methods for rate 3/4 trellis code have similar performance,but the first has less computational effort and can be implemented conveniently.Meanwhile,the new algorithm for QR decoding avoids solving the complicated error polynominal and has better performance.更多还原