一种基于CDMA/TDMA混合多址的GSM与CDMA扩容方法

提出了一种基于CDMA/TDMA混合多址的GSM与CDMA扩容方法。在发送端,通过扩频码对GSM信号进行直接序列扩频,使其多址方式由TDMA变换为CDMA/TDMA,然后与CDMA信号在空间同频传输,这样就可以解决两个系统在Um接口的兼容问题;在接收端,使用相同的扩频码对CDMA/TDMA信号进行解扩,使其多址方式由CDMA/TDMA还原为TDMA,由此可以将GSM与CDMA两种信号进行分离。文章提出了用互补码集作为多址接入码,并给出了一个时隙内GSM用户被扩频调制的具体过程。理论分析和仿真结果表明,该方法可使系统总容量扩大2倍。

A Novel Scheme for Enhancing the Capacity of CDMA and GSM Systems Based on CDMA/TDMA Multiple Access

This paper puts forward a novel scheme for enhancing the capacity of CDMA and GSM Systems based on CD MA/TDMA multiple access.First,at the transmitter,GSM signals will be multiplied by PN sequences to be transferred from TDMA mode to CDMA/TDMA mode.Then they will transmit with CDMA signals on the same bandwidths,so the U_m interface combination problem of these two systems can be solved.At the receiver,CDMA/TDMA signals will be multiplied by the same PN sequences to be transferred to TDMA mode,and these two signals can be separated.This paper proposes using complementary code as multiple access codes and gives the process of single GSM user be spead and modulated in one time slot.It can be seen from theory analysis and simulation results that this method can double increase the total system capacity.