The performance of cross-coupled, M-ary quadrature amplitude modulation (QAM) systems is determined for the case in which bandwidth efficient trellis codes are used to combat interference. Performance with and without compensation for cross-coupled interference is presented. It is found that simple trellis codes can maintain the error probability at an acceptable level for cross-coupling parameters that render uncoded systems unusable. Up to two-dimensional trellis codes are considered for four-dimensional QAM signals. The average probability of the most likely error events is calculated by using the method of moments. The results are applicable to any digital communication system using multidimensional quadrature amplitude modulation, e. g. , voiceband modems and cross-polarized radio systems. It is found that simple trellis codes have coding gains of more than 5 dB in cross-coupling interference compared to 3 dB for a Gaussian channel.
|Original language||English (US)|
|Number of pages||6|
|Journal||Conference Record - International Conference on Communications|
|State||Published - 1986|
All Science Journal Classification (ASJC) codes
- Computer Networks and Communications
- Electrical and Electronic Engineering