In this paper

we proposed an efficient joint source channel rate control algorithm for real time wireless video transmission which use automatic repeat request scheme to retransmission the error packet. The two state Markov model was used to simulate the wireless channel

and the Cauchy distribution based rate and distortion model were used as the source model. In the new scheme

at frame level

a PID controller based buffer control algorithm was developed to improve the buffer control ability which allocated frame target bit based on the channel bandwidth and buffer status; at macroblock level

the frame bit budget was distributed among macroblocks using the new rate distortion model and Lagrange optimization method. Experimental results show that

the proposed algorithm can improve the average PSNR and decrease the number of skipped frames significantly.