Study on the suitability of LDPC combined with diversity technique in broadband wireless systems

This report lays out the idea of introducing LPDC codes along with the spreading sequence to improve noise immunity of the signals traversing in wireless environment. With the need to make communication techniques efficient and reliable, spread spectrum has gained importance for its various added advantages. LDPC (Low Density Parity Check) have been gaining limelight in the past few years. Comprising of relatively faster encoding and decoding techniques, LDPC codes are capable of recovering the original message even after a large part of the message has been corrupted. To achieve lesser BER, spread spectrum concept has been used along with LDPC codes. In this paper, the signal was first spread and then the encoding and decoding algorithms were employed. The original message is finally recovered after de-spreading the signal. Features such as Approaching Shannon capacity, Good block error correcting performance, and Low error floor can be exploited by this technique. The presented idea would be applied to broadband wireless systems such as Wi-Fi and Wi-Max. This work demonstrates the suitability of LDPC along with spread spectrum technique in broad band wireless systems.