tailieunhanh - Báo cáo hóa học: " Resource allocation for maximizing outage throughput in OFDMA systems with finite-rate feedback"

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: Resource allocation for maximizing outage throughput in OFDMA systems with finite-rate feedback | Wu et al. EURASIP Journal on Wireless Communications and Networking 2011 2011 56 http content 2011 1 56 o EURASIP Journal on Wireless Communications and Networking a SpringerOpen Journal RESEARCH Open Access Resource allocation for maximizing outage throughput in OFDMA systems with finite-rate feedback Bo Wu 1 Lin Bai2 Chen Chen1 and Jinho Choi3 Abstract Previous works on orthogonal frequency division multiple access OFDMA systems with quantized channel state information CSI were mainly based on suboptimal quantization methods. In this paper we consider the performance limit of OFDMA systems with quantized CSI over independent Rayleigh fading channels using the rate-distortion theory. First we establish a lower bound on the capacity of the feedback channel and build the test channel that achieves this lower bound. Then with the derived test channel we characterize the system performance with the outage throughput and formulate the outage throughput maximization problem with quantized channel state information CSI . To solve this problem in low complexity we develop a suboptimal algorithm that performs resource allocation in two steps subcarrier allocation and power allocation. Using this approach we can numerically evaluate the outage throughput in terms of feedback rate. Numerical results show that this suboptimal algorithm can provide a near optimal performance with a performance loss of less than 5 and the outage throughput with a limited feedback rate can be close to that with perfect CSI. Keywords Orthogonal frequency division multiple access OFDMA limited feedback quantized channel information rate-distortion resource allocation two-step suboptimal algorithm 1 Introduction Orthogonal frequency division multiplexing OFDM is a promising technique for the next-generation wireless communication systems. OFDM divides the frequency-selective fading channel into N orthogonal flat-fading subcarriers to provide a high data rate. Orthogonal .