非线性功放对数字调制信号的影响研究

Nonlinear amplifier effects in digital modulation signals

功放的非线性会带来调制信号的性能恶化,基于simulink建模,对比仿真了恒包络调制MSK和非恒包络调制BPSK,在功放线性和非线性区域时的误码性能,以及在带宽受限条件下,相邻信道干扰对信号误码性能影响。仿真结果表明,功放饱和对非恒包络调制信号影响更大,尤其是信道间隔较小的情况下,非恒包络调制信号的误码性能恶化严重。该研究为数字通信系统的工程设计提供了一种可借鉴分析方法。

The nonlinearity of amplifier makes the performance of modulation signals deteriorated. This paper establishes a simulation model by using Simulink, and bit error rate of constant envelope modulation （MSK） and non-constant envelope modulation （BPSK） signals through the linear and nonlinear power amplifier are simulated, and under the condition of band- width constraints, the impact of adjacent channel interference on bit error rate is analyzed. Experimental results show that nonlinear power amplifier has a greater impact on non-constant envelope-modulation, and especially in the case of smaller channel-space, the bit error rate performance of the non-constant envelope-modulation has deteriorated sharply. The paper provides an analysis method for practical digital communication system.