Trellis coded spread -spectrum modulation schemes with multiple -access interference and coded modulation schemes in a fading environment.

Abstract

In this research, the performance of orthogonal, biorthogonal, Nordstrom-Robinson, Reed-Muller, and Kerdock codes in various trellis-coded versions is examined under different channel fading conditions, and with multiple-access interference. The trellis coded Nordstrom-Robinson, Reed-Muller, and Kerdock codes can achieve high input rate while maintaining a certain minimum distance, and thus low error rate is obtained at high signal-to-noise or signal-to-interference ratio. Also, adaptive coding can be applied on different input bits of the trellis coded modulation schemes. An outer code can be concatenated with trellis coded modulation schemes to further reduce error probability. Also, a new coded modulation scheme is applied to orthogonal, biorthogonal, Nordstrom-Robinson, Reed-Muller, and Kerdock codes. When a binary convolutional code is bit interleaved and concatenated with this new coded modulation scheme, significantly larger overall distances are possible. This can be achieved for both coherent and noncoherent demodulation. Different multicast schemes are considered and compared with the new coded modulation scheme. Several realistic fading channel models of mobile communication are proposed, and the application of the new coded modulation scheme over various fading channel models is examined. Various input rates are assumed under realistic assumptions, and their performances are examined and compared.