tailieunhanh - Báo cáo hóa học: " Research Article Analysis of Coded FHSS Systems with Multiple Access Interference over Generalized Fading Channels"

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 Analysis of Coded FHSS Systems with Multiple Access Interference over Generalized Fading Channels | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2008 Article ID 346730 9 pages doi 2008 346730 Research Article Analysis of Coded FHSS Systems with Multiple Access Interference over Generalized Fading Channels Salam A. Zummo Department of Electrical Engineering KingFahd University of Petroleum and Minerals KFUPM Dhahran 31261 Saudi Arabia Correspondence should be addressed to Salam A. Zummo zummo@ Received 14 April 2008 Revised 30 June 2008 Accepted 11 August 2008 Recommended by Ibrahim Develi We study the effect of interference on the performance of coded FHSS systems. This is achieved by modeling the physical channel in these systems as a block fading channel. In the derivation of the bit error probability over Nakagami fading channels we use the exact statistics of the multiple access interference MAI in FHSS systems. Due to the mathematically intractable expression of the Rician distribution we use the Gaussian approximation to derive the error probability of coded FHSS over Rician fading channel. The effect of pilot-aided channel estimation is studied for Rician fading channels using the Gaussian approximation. From this the optimal hopping rate in coded FHSS is approximated. Results show that the performance loss due to interference increases as the hopping rate decreases. Copyright 2008 Salam A. Zummo. 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 A serious challenge to having good communication quality in wireless networks is the time-varying multipath fading environments which causes the received signal-to-noise ratio SNR to vary randomly. One solution to fading is the use of spread spectrum SS techniques which randomizes the fading effect over a wide frequency band. The main types of SS are the direct sequence