Dynamic switching between maximum likelihood sequence estimation (MLSE) and linear equalizer for single antenna interference cancellation (SAIC) in a global system for mobile communications (GSM) system

摘要

In a GSM/EDGE Single Antenna Interference Cancellation (SAIC) operation environment, a mobile station is required to operate in a wide range of interference levels. An SAIC linear equalizer that takes advantage of the GMSK signal structure performs better than a conventional Maximum Likelihood Sequence Estimation (MLSE) equalizer in high interference levels, while it performs worse in low interference levels. A dynamic selection between the SAIC linear equalizer and the MLSE equalizer for each received burst is achieved to provide the optimal performance across the entire required operation environments. The dynamic selection is based on the estimated noise plus interference energy relative to the total received signal energy. The soft information calculated by the two categories of equalizers is properly scaled to generate soft information with balanced magnitude.