频谱失配下的变换域通信系统基函数优化设计

针对频谱失配条件下变换域通信系统接收端误码性能下降的问题,提出了一种新的基函数优化设计方法。该方案可针对不同失配情况动态设计基函数的可用频点,实现频谱失配条件下系统抗干扰性能和频带利用率的最优化权衡，从而提升频谱失配条件下系统的误码性能。首先，建立远距离变换域通信系统模型，分析收发端电磁干扰环境。其次，通过分析频谱失配条件下基函数性能,理论推导系统误码率表达式,进而建立基函数幅度谱的最优化模型,并采用最速下降法进行最优解的搜索。仿真结果表明,与现有方法相比,本文所提方法更合理的设计了基函数幅度谱,在不同失配率下系统的抗干扰性能有明显提升,同时具有更好的信噪比误码性能。 

Optimal Design of Basic Function of Transform Domain Communication System under Spectrum Sensing Mismatch

For the problem of the performance of the bit error rate (BER) at the receiving end of the transform domain communication system (TDCS) under the spectrum sensing mismatch condition, a new optimization design of basic function is proposed. The method can dynamically design the available frequency of the basic function for different mismatch conditions, and achieve the optimization trade-off between system anti-interference performance and frequency band utilization under spectrum sensing mismatch, thereby improving the BER performance of system under spectrum sensing mismatch. Firstly, the model of long-distance TDCS is established, and the electromagnetic interference environment of transceiver and receiver is analyzed. Secondly, by analyzing the performance of the basic function under the spectrum sensing mismatch condition, deriving the system BER expression theoretically, the optimal model of the basic function amplitude spectrum is established and the steepest descent method is used to search the optimal solution. The simulation results show that compares with the existing methods, the proposed method makes a more reasonable design of the basic function amplitude spectrum, and the anti-interference performance is significantly improved under different mismatch ratios, and has better Signal-to-noise ratio BER performance.