The BER performance optimization of ultra wideband TH-PPM in a multi-path environment

This paper is focuses on the unbalanced bit error rate(BER)for different transmitted data symbols of ultra wideband(UWB)impulse radio time-hopping pulse-posi-tion-modulation(TH-PPM)in a deterministic multi-path environment for unreasonable parameter selection.Two solutions are presented here.The first is that the decision threshold of RAKE is dynamic for different channel environments;the other is that we can improve the tra-ditional TH-PPM modulation,which is,encoding the trans-mitted data symbol with balance code.It is shown by theoretical analysis and computer simulation that these two methods can solve the unbalanced BER of traditional TH-PPM.Compared with the dynamic threshold method,the balance encoding scheme can be implemented more easily,and is more robust to the channel time variant char-acteristics,the channel estimation of RAKE receiver and the combination techniques.