A research study submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Advanced Technologies

Research Studies Project Report (M. Eng.) - Asian Institute of Technology, 1997

The evolution of the multimedia era demands highly reliable transmission of video, audio and the associated data in wireless medium. Contemporary research has proved that ATM is going to be the prominent transport media for integrated traffic in the years to come. The understanding of the performance of ATM in wireless channel is essential, considering the plethora of information to be exchanged through this channel in the future. This paper presents an adaptable error control scheme for ATM wireless integration. The inherent characteristics of ATM such as variable bit rate and bandwidth are the latent factors crippling the conventional error control schemes. The analysis of ATM performance in this perspective was the motive behind the design of an adaptable scheme. A novel coding scheme is designed based on Reed Solomon block coding technique and the performance of the same is thoroughly analyzed in frequency selective Rayleigh fading channel. The analysis of the punctured coding in terms of BER showed that the performance cannot be improved with out increasing the error correction capability of the code. BER of (255,223, 10) punctured scheme and (255,223) fixed scheme almost tracks each other even at BER as low as 5x10-3 . The difference in coding gain for the fixed scheme and punctured scheme with t=l6+0.4x 10 is almost l.2dB at a reference BER of 10-4 . The study points out that the performance in terms of bandwidth and BER can be simultaneously achieved only if the error correction capability of the code is increased along with puncturing. The performance of the coding scheme should be evaluated for more stringent MPSK modulation schemes which have higher bandwidth efficiencies and tight SNR requirements as the current analysis considers only QPSK modulation. The accurate modeling of the channel and appropriate modulation scheme combined synergistically with the proposed adaptive RS scheme for error controlling, can be used in the future ATM systems.