A novel code-based iterative PIC scheme for multirate CI/MC-CDMA communication

Mithun Mukherjee,Preetam Kumar

doi:10.1186/1687-1499-2011-155

Abstract

This paper introduces a novel code-based iterative parallel interference cancellation technique (Code-PIC) for the multirate carrier interferometry/multicarrier code division multiple-access (CI/MC-CDMA) system, which supports simultaneous transmission of high and low data rate users. In Code-PIC scheme, multiple-access interference (MAI) for the desired user is estimated based on the projection of subcarrier and subsequent removal of interference from the received signal depending on specific high or low data rate users. Carrier interferometry (CI) codes are used to minimize the cross-correlation between users, which significantly reduces the multiple-access interference (MAI) for the desired user. The effect of MAI in CI/MC-CDMA is reduced by giving proper phase shift to different set of users. Improved estimation of MAI in Code-PIC results in lower residual interference after interference cancellation. Simulation results show that Code-PIC scheme offers improved BER performance over AWGN and Rayleigh fading channels compared to Block-PIC and Sub-PIC with reduced latency and complexity.

Highlights

Multicarrier code division multiple-access (MC-CDMA) system is a promising technique for high-speed communication system due to robustness against intersymbol interference (ISI) over multipath
8 Conclusion In this paper, Code-parallel interference cancellation (PIC) scheme is introduced for multirate Carrier interferometry (CI)/MC-CDMA system
The performance is compared with Block-PIC and subcarrier PIC (Sub-PIC) with hard and soft estimates of received data bits over additive white Gaussian noise (AWGN) and frequency selective Rayleigh fading channels

Summary

Introduction

Multicarrier code division multiple-access (MC-CDMA) system is a promising technique for high-speed communication system due to robustness against intersymbol interference (ISI) over multipath. Exp(bi,k), where ai,k and bi,k are complex channel gain and carrier phase offset for ith subcarrier of kth user, respectively. The BER performance of Sub-PIC improves significantly by taking soft estimation of the interfering users.

Results

Conclusion