Performance Degradation in Pre-rake Frequency-division Duplex/ Direct Sequence-code Division Multiple Access Systems

Defence Science Journal

C. Subhas³  Y. Venkatarami Reddy²  K. Rama Naidu¹ 

[1] JNTU College of Engineering, Anantapur;Andhra Pradesh Public Service Commission, Hyderabad;Sree Vidyanikethan Engineering College, Tirupati

关键词: Direct sequence-code division multiple access;    DS-CDMA;    rake receiver;    pre-rake;    inter-symbol interference;    frequency-division duplex;    FDD;    channel prediction;   

DOI  :  

学科分类：社会科学、人文和艺术（综合）

来源: Defence Scientific Information & Documentation Centre

【 摘 要 】

The transmitter-based pre-rake diversity combining technique reduces the complexity, size and cost of the mobile unit (MU), while achieving the same inter symbol interference (ISI) mitigation effects of rake receiver for direct sequence-code division multiple access (DS-CDMA) systems. The technique is based on preprocessing of transmitted signal relying on knowledge of the channel state information (CSI) before transmission. In most of the previous works, this a priori information is either assumed or estimated for the uplink and the same is applied to the downlink in time division duplex (TDD) systems due to channel reciprocity. In this paper, a method for channel prediction to evaluate the pre-rake system using binary phaseshift keying (BPSK) modulation in frequency-division duplex (FDD) through analytical and computer simulations for DS-CDMA downlink has been proposed. The performance of the system was also evaluated under ideal and predicted channel conditions using different spreading codes. The findings will have widespread applications in defence communication equipment. Defence Science Journal, 2010, 60(3), pp.282-289 , DOI:http://dx.doi.org/10.14429/dsj.60.355

【 授权许可】

Unknown