tailieunhanh - Báo cáo hóa học: " Research Article Minimum BER Receiver Filters with Block Memory for Uplink DS-CDMA Systems"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Minimum BER Receiver Filters with Block Memory for Uplink DS-CDMA Systems | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2008 Article ID 462710 12 pages doi 2008 462710 Research Article Minimum BER Receiver Filters with Block Memory for Uplink DS-CDMA Systems Are Hjorungnes1 and Merouane Debbah2 1 UNIK - University Graduate Center University of Oslo Instituttveien 25 . Box 70 2027 Kjeller Norway 2 Alcatel-Lucent Chair on Flexible Radio Ecole Superieure d Electricite Plateau de Moulon 3 Rue Joliot-Curie 91192 Gif-sur-Yvette Cedex France Correspondence should be addressed to Are Hjorungnes arehj@ Received 24 September 2007 Revised 28 January 2008 Accepted 10 March 2008 Recommended by Tongtong Li The problem of synchronous multiuser receiver design in the case of direct-sequence single-antenna code division multiple access DS-CDMA uplink networks is studied over frequency selective fading channels. An exact expression for the bit error rate BER is derived in the case of BPSK signaling. Moreover an algorithm is proposed for finding the finite impulse response FIR receiver filters with block memory such that the exact BER of the active users is minimized. Several properties of the minimum BER FIR filters with block memory are identified. The algorithm performance is found for scenarios with different channel qualities spreading code lengths receiver block memory size near-far effects and channel mismatch. For the BPSK constellation the proposed FIR receiver structure with block memory has significant better BER with respect to Eb N0 and near-far resistance than the corresponding minimum mean square error MMSE filters with block memory. Copyright 2008 A. Hjorungnes and M. Debbah. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION CDMA is a multiple access technique where the user separation is done .