瑞利衰落信道下SR-ARQ-AMS系统时延性能研究-系统工程学报.PDF

27 4 Vol.27 No.4 2012 8 JOURNAL OF SYSTEMS ENGINEERING Aug. 2012 SR-ARQ-AMS , , , (1. , 730050; 2. , 730050) : , (SR-ARQ)(SR-ARQ-AMS) , Markov. , M/G/1. , . , . SR-ARQ-AMS . : SR-ARQ-AMS; ; ; Markov : O226; N945.12; TN915.01 : A :2012 On delay performance of SR-ARQ-AMS over Rayleigh fading channels LI Suo-ping , GAO Yan , HOU Shang-lin , MA Cheng-ye (1. School of Science, Lanzhou University of Technology, Lanzhou 730050, China; 2. Key Laboratory of Gansu Advanced Control for Industrial Processes, Lanzhou University of Technology, Lanzhou 730050, China ) Abstract: Conventional adaptive transmission schemes performed poorly in wireless correlated slow-fading channels. The transmission scheme and the system model of adaptive modulation system combined with selective repeat automatic repeat request (SR-ARQ) over Rayleigh fading channels is analyzed firstly, a finite- state Markov chain is modeled for describing Rayleigh fading channels and adaptive modulation system. A queuing model with vacations is established by using the equivalent service delay method. The expression of system’s main performance measures, such as system’s average waiting delay time, average delay time and normalized maximum throughput are gained, which take into account the delay of lost packet transmitting limited times. The influence of various parameters on system delay is analyzed by numerical simulation and then we obtain the method to enhance system transmission efficiency. Numerical results show that SR-A