On the Joint Detection SAIC Algorithm in Asynchronous GSM Network
Zhigang Tian, Wenbin Guo, Dacheng Yang · 2005
As a crucial convolution step, SAIC (single antenna interference cancellation) has been introduced into GSM system. Great capacity gain could be achieved with SAIC applied, and a feasible study is being conducted in 3GPP. Since most of GSM networks are operated in asynchronous mode, the development and evaluation of SAIC algorithm in asynchronous network is necessary. Equivalent discrete channel model of interference in asynchronous case is analyzed, and one symbol more ISI is caused for asynchronous interference than synchronous desired signal. The asynchronous model brings about some obstacles to the channel estimation and detection. Refined JMLSE (joint maximum likelihood sequence estimation) is developed to deal with asynchronous model. Two LS (least square) channel estimation methods - joint LS (JLS) and iterative LS (ILS) - are also proposed to provide JMLSE channel information and their performances are analyzed in asynchronous case.