Research And Implentment Of Equalization In Lte Uplink

To keep the competitiveness of 3G in ten years, Long Term Evolution Project was passed though by 3GPP in the late of year 2004. The purpose of LTE is to improve the transmission rate, reduce the system delay, increase the system capability and the coverage area, and reduce the operational costs. LTE is the importance of various large communication equipment corporation. And taking a research of the LTE technology is full of significance.If modulation bandwidth exceeds the correlated bandwidth of wireless channel in signal modulation, inter-symbol interference will be produced and modulation signal will broaden. In this case, putting equalizer into receiver can effectively compensate the amplitude and delay of channel. Equalizer can reduce the inter-symbol interference and improve the transmission quality of the communication link, without increasing transmission power and bandwidth.The low complexity frequency domain equalizer can be adopted in receiver by using of SC-FDMA in LTE uplink. The technology of frequency domain equalizer is very important in LTE uplink, which is great influence to system performance. The paper takes a research on the application of frequency domain equalizer in LTE uplink.Based on widely literature datum, the structure of LTE uplink, the realization principle of partial modules and system parameters are given.Two traditional linear frequency domain equalizer, ZF and MMSE equalizer are used in LTE uplink and simulated in matlab. The results are analyzed according to the BER.The application of frequency domain decision feedback equalizer in LTE uplink is emphatically analyzed. According to the feedback position and precision of feedback signal, three approaches of decision feedback equalizer are presented. They are Frequency domain Direct Feedback, Physical channel Data Feedback and Terminal Error Data Feedback. Use algorithm of MMSE-RISIC which is low complexity. They are simulated in matlab in LTE uplink. They are more advanced and more improvement compared with linear equalizer. Three DFEs is implemented by C language and get cycle in MSC8156 DSP. At last, draw the schedulings of uplink system using new equalizer. MMSE-FDE equalizer is used in demo and show a good performance.