HFC上行信道S-CDMA接入的多用户检测

Multiuser Detector for HFC Upstream Channel Using S-CDMA Access

分析了 ＨＦＣ上行信道的特点，提出使用Ｓ－ＣＤＭＡ技术可以在极低的信噪比下获得稳固的传输特性。讨论了多种检测接收方案，并将解相关判决反馈多用户检测算法应用于ＨＦＣ上行信道Ｓ－ＣＤＭＡ系统的接收，利用消除强功率信号的干扰达到弱功率信号的正确判决，达到有效地消除多址干扰和抗远近效应目的。其算法的复杂性与用户数成正比，每个用户只需作一次判决。系统不需要精确的同步和功率控制，从而简化了系统。

This paper analyzes the characteristic of HFC upstream channel, proposes that using SCDMA can obtain stable transmission on the condition of very low SNR. S-CDMA has an ability to resist many kind of narrow-band interference and noises, but the multi-access interference induces the capacity and performance of the system. After analyzing several multiuser detectors, this paper uses decorrelating decision-feedback detector in HFC upstream channel S-CDMA system. It can cancel the interference of the stronger users and make advantages to the decision of the weaker users, thus can cancel the multiaccess interference and has better near-far resistance. Its complexity is linear in the number of users. The system need not accurate synchronization control, thus is simplified.