One-User/One-Group Soft-Decision Aided Multiuser Detection for 2D Spread MC DS-CDMAs

Hoang-Yang Lu,I-Hsuan Lai

doi:10.4236/cn.2013.53b2023

Abstract

We consider the uplink of a multiuser, multiple-input multiple-output (MIMO), frequency-time-domain spread, multi- carrier (MC), direct sequence code division multiple access (DS-CDMA) system. As other CDMA-like systems, the multiple access interference (MAI) effect still exists in such an MC DS-CDMA system. To mitigate the MAI effect, we propose user-based and group-based layered detection schemes. Specifically, to enable a trade-off between the performance and the computational complexity, the schemes only use one user's/group's soft decisions for user-based/ group-based layered detection. The results of simulations demonstrate that the proposed schemes outperform existing approaches, and their computational complexity is modest.

Highlights

The rapidly increasing demand for better quality of service (QoS) in wireless systems has motivated the development of several promising approaches to improve system capacity and transmission reliability
We consider the uplink of a multiuser, multiple-input multiple-output (MIMO), frequency-time-domain spread, multicarrier (MC), direct sequence code division multiple access (DS-CDMA) system
As other CDMA-like systems, the multiple access interference (MAI) effect still exists in such an MC DS-CDMA system

Summary

Introduction

The rapidly increasing demand for better quality of service (QoS) in wireless systems has motivated the development of several promising approaches to improve system capacity and transmission reliability. One promising multiple access approach for sharing valuable bandwidth resources is called multi-carrier (MC) direct sequence code division multiple access (DS-CDMA) [1,2]. A new MC scheme, called frequency-time-domain (FT-domain) spread MC DS-CDMA, was proposed in [3]. The scheme first spreads the transmitted symbol by a time-domain (T-domain) signature code. The Tdomain spreading signal is copied to each subcarrier to be spread by a frequency-domain (F-domain) signature code. In addition to providing the superior capacity performance gain, FT-domain spread MC DS-CDMA systems have other attractive features, such as short and low-chip-rate signature codes for realizing low-rate signal processing [4]

Objectives

Results

Conclusion