Adaptive multidimensional coded modulation over flat fading channels

We introduce a general adaptive coding scheme for Nakagami multipath fading channels. An instance of the coding scheme utilizes a set of 2 -dimensional (2 -D) trellis codes originally designed for additive white Gaussian noise (AWGN) channels. Any set of 2 -D trellis codes for AWGN channels can be used. Sets for which all codes can be generated by the same encoder and decoded by the same decoder are of particular interest. A feedback channel between the transmitter and receiver makes it possible to transmit at high spectral efficiencies under favorable channel conditions and respond to channel degradation through a smooth reduction of the spectral efficiency. We develop a general technique to determine the average spectral efficiency of the coding scheme for any set of 2 -D trellis codes. As an illustrative example, we calculate the average spectral efficiency of an adaptive codec utilizing eight 4-D trellis codes. The example codec is based on the International Telecommunications Unio...

• Type: Journal
• Year: 2000
• Where: JSAC
• Authors: Kjell Jørgen Hole, Henrik Holm, Geir E. Øien
• Keywords: -D Trellis Codes, Coding Scheme, JSAC 2000, Spectral Efficiency