DYNAMIC SWITCHING BETWEEN MLSE AND LINEAR EQUALIZER FOR SINGLE ANTENNA INTERFERENCE CANCELLATION IN A GSM COMMUNICATION SYSTEM

摘要

In a GSM/EDGE Single Antenna Interference Cancellation (SAIC) operation environment, a mobile station (110) is required to operate in a wide range of interference levels. An SAIC linear equalizer (74) that takes advantage of the GMSK signal structure performs better than a conventional Maximum Likelihood Sequence Estimation (MLSE) equalizer (76) in high interference levels, while it performs worse in low interference levels. A dynamic selection (72) between the SAIC linear equalizer (74) and the MLSE equalizer (76) for each received burst is achieved to provide the optimal performance across the entire required operation environments. The dynamic selection (72) is based on the estimated noise plus interference energy (150) relative to the total received signal energy (153). The soft information (320) calculated by the two categories of equalizers is properly scaled (318 , 420) to generate soft information (320) with balanced magnitude.