摘要
针对通过基于不变分布阈值量化方法得到的单向耦合映象格子序列互相关性差和利用率低的问题，提出了一种基于Tent映射的双向耦合映象格子和改进型不变分布阈值量化相结合的设计方法。为实时产生高性能的DS码，提出了通过预设最优映射参数和序列选取方式的优选方法来产生优选序列。最后对DS码进行了随机性测试和DS／CDMA系统误码率分析。仿真表明，与多比特量化方法相比，经改进型不变分布阈值量化方法得到的基于Tent映射的双向耦合映象格子序列在其他性能不降低的情况下，平衡性得到了提高，同时序列的利用率较高，实时优选出的DS码的各项性能得到了进一步的提高。
Aiming at the problem of bad cross-correlation and low utilization rate of the OCML sequences based on the quantitative method of the invariandy distributing threshold, a design combining the modified quanti- tative method of the invariandy distributing threshold and TDCML-map is presented. In order to generate a DS code with good performance in real-time, an optimal method by presetting the best map parameters and the mode of sequence selection is proposed. Finally, the randomicity of these DS codes is tested and the bit error rate of DS/CDMA system with these DS code is analyzed. Simulation results prove that, compared with the multi-bit quantitative method, the balance of TDCML sequences based on the modified method mentioned above is improved, while other performances do not decreased; meanwhile, the utilization percent of TDCML sequences is higher. The performance of optimal DS codes selected in real-time has been further improved.
出处
《通信对抗》
2011年第3期7-12,共6页
Communication Countermeasures
关键词
DS码
不变分布
量化
优选
DS code
invariant distribution
quantification
optimization
