Design Of Equalization Algorithm For Multimode Communication Signal

With diversified modulation methods nowadays,the environment for modulating signals is increasingly complex.Because that different modulation signals have different modulation characteristics,which are affected differently in the signal transmission process,it is proposed to design different equalization processing schemes for signals of different modulation modes in order to solve the signal distortion problems such as interference and multipath fading of the modulation signals generated in the channel transmission process.For phase-amplitude-modulated signals,increasing its phase state number or amplitude level order can promote its spectrum efficiency,but it also leads to an increase in inter symbol interference(ISI).The thesis proposes a time-domain adaptive blind equalization algorithm to resolve it.The constant modulus algorithm(CMA)can be used to process constant modulus phase-modulated(MPSK)signals;For signals that do not have constant modulus characteristics(such as MQAM),it is proposed to use multi-modulus algorithm(MMA)to deal with it;This thesis also uses the same method to study the cross-polarization channel interference cancellation technology.For a continuous phase modulation(CPM)signal that also has a high in-band spectrum utilization rate,ISI can easily occur due to its phase correlation.As the time domain demodulation structure of the CPM signal is very complicated,the single carrier frequency domain equalization algorithm with relatively simple structure is designed to perform CPM equalization.Multi-carrier Orthogonal Frequency Division Multiplexing(OFDM)technology is widely used in communication systems known as highly spectrum efficiency.But multi-path interference exists also leading the serious ISI.By the advantage of OFDM frequency domain processing,the thesis intends to design a multi-carrier frequency domain equalization algorithm.Based on above simulation of equalization algorithm,the thesis provides the implementation,and experimental verification on a FPGA logic module.