The method for recovering the soft information in the protocol stacks in type of WIFI and WIMAX

The paper will present the method for recovering the soft information in the protocol stacks in type of WIFI and WIMAX, which is based on the joint source-channel decoding (JSCD) techniques with enhanced permeable layer mechanism used for wireless multimedia transmission. Packet header recovery at varieties of protocol layers using MAP estimation is the cornerstone of the proposed method. The inherently obtainable correlation of intro-layer and inter-layer header proves to be effective in picking out a simplified set of header configurations for further processing. The best candidate is then obtained using the soft decoding of CRC or Checksum protected data and CRC or Checksum redundancy itself. Finally, with a simulating program written by C++, we can prove that a multimedia transmission system added an AWGN channel (Gaussian noise of zero mean and variance s 2 ) using the method proposed in the paper can really obtain a significant improvement of ENR at the receiver, and effective make the band of transmission much wider and the quality of transmission much better.