介绍一种在发送端通过两次调制对已知特定信道特性进行预补偿的方法,该方法先将频带信号调制到一个低频上进行预补偿处理后再调制到最终的频率上。采用Simulink仿真,给出在π/4-DQPSK调制系统中采用此方法有效实现了对某种有线信道的频率线性衰减特性的预补偿,该方法在减轻接收端负担的同时,提高了系统的可靠性。
The two modulation methods that achieve pre - compensation on the known channel is introduced. It follows that first modulation then pre - compensation the last the second modulation. The method is applied to π/4 - DQPSK modulation system to accomplish pre- compensation on the frequency.linear attenuation channel, which ont only improves system reliability but also reduces the burden of receiver.