Research On Single Antenna Interference Cancellation Technology

In the GSM system, the utilization of lower frequency reuse factor can improve the efficiency of spectrum, however causing co-channel interference in system. There exists a restriction that the mobile terminal can only adopt one receiving antenna, so the challenge of co-channel interference cancellation is mainly from the downlink.The article begins with an introduction to the co-channel interference in GSM which leads to the necessary application of a single antenna interference cancellation technology and its classification and development are also presented. According to the comparison of the realization of multi-user detection with that of blind interference cancellation, the thesis decides to do some research on the later. The thesis analyzes the Laurent component of the constant-envelope continuous phase modulation GMSK signal and the principles of the conventional GMSK linear receivers. Based on the structure of conventional linear receivers and one-dimensional characteristic of approximation after the linear calculation of GMSK signal, two kinds of low-complexity single antenna interference cancellation algorithm are designed. One is based on different space which is from districts to receivers to distinguish interference and the desired signals, and the other is to do the process of diversity-combining on baseband signal for it has the same information in real and false parts. Finally, two kinds of algorithm performance are simulated and evaluated respectively.