EBPSK调制波的正交性及功率谱分析

Orthogonality and Power Spectra of EBPSK Modulated Waves

波形正交性与功率分布特性直接关系到信号的解调与带宽.通过导出EBPSK调制相关解析式和功率谱表达式,并进行计算机仿真,给出EBPSK正交解与功率谱分布,得到占空比为1,相移π/2的正交功率谱最优解,指导EBPSK波形参数选择.符号相关性大,功率分布集中,但解调性能差;符号相关性小,解调性能好,但功率分布扩散.最优正交EBPSK波形的功率谱,减少了线谱分量,功率分布集中,频谱得到压缩,带宽效率得到改善;同时,符号正交,解调相对容易,符号的正交性和带宽的高效率得到较好的折衷.

Waveform orthogonality has a direct influence on signal bandwidth and demodulation. The paper obtains orthogonal EBPSK signals and power spectrum by deriving EBPSK correlative expression and power spectrum expression. The best power spectrum condition, duty cycle of one and phase shift of π/2, are given. This is helpful in parameter selection of EBPSK waveform control. As the symbol correlativity is increased, the power is more concentrated but with poorer demodulation performance. On the other side, with performance of demodulation is improved, can reduce line spectrum components, but power becomes more distributed. The make power concentrated and spectra symbol eorrelativity decreased, best orthogonal power spectrum compressed. Thus bandwidth efficiency is improved and, at the same time, performance of demodulation is also improved for symbol orthogonality. Therefore a good tradeoff between symbol correlativity and demodulation performance is obtained.