CDMA系统自适应抗远近效应接收机的研究

The Adaptive Near-far Resistant Receiver for DS CDMA System

通过研究 CDMA系统的抗远近效应技术 ,推导了异步系统的等价同步离散时间模型 ,提出了采用自适应分数间隔接收机代替传统的相关接收机 ,并对其进行了仿真研究 ,给出了实验结果。这种接收机在只需知道接收用户的地址码 ,无需干扰用户的任何信息的条件下进行多址干扰 (MAI)抑制 ,具有抗远近效应能力。仿真研究结果表明 ,自适应接收机可以在远近效应环境中工作 ,其性能具有较大的改善 ,特别适合移动台中采用。

This paper presents a novel near far resistant receiver for DS CDMA system. We employ the adaptive fractionally spaced receiver to replace the conventionally matched filter receiver. The former is near far resistant. This structure requires only the signature waveform and timing of the desired user and can suppress MAI without interfering user's information regarding their timing or the signature waveform.From the results of computer simulaton,the adaptive receiver can work well in near far environment,and it is fit to use in the mobile receiver.