Study on Implementation Technology of Channel Estimation in OFDM System Based on DSP
|School||Harbin Institute of Technology|
|Course||Communication and Information System|
|Keywords||orthogonal frequency division multiplexing WiMAX LTE channel estimation DSP implementation|
The multipath fading and Doppler shift have the greatest impact on the mobile business of broadband wireless, but Orthogonal Frequency Division Multiplexing (OFDM) is a highly efficient digital transmission technology which has the advantages of anti-multipath ability, high utilization of the spectrum and simple to achieve with hardware and it is being regarded as one of the core technology in the next-generation wireless communications.This paper emphatically discussed the channel estimation technology of OFDM system in the wireless broadband mobile communication environment and research on the channel estimation algorithm and implementation technology based on the wireless Metropoliatan Area Network IEEE 802.16e and OFDM physical layer protocol standards of long-term evolution (LTE) protocol of 3 GPP and it is also in close connection with the latest developments of OFDM technology. The research results optimizing the performance from the engineering point have some instructional significance for the application of actual engineering on the premise of ensuring function.This paper first summarized the development history and status of OFDM technology and then summarized the channel estimation technologies in OFDM system; Further analyzed the basic principles of OFDM system and mostly research on the channel estimation algorithm based on pilot symbols in OFDM Systems including the LS algorithm, MMSE algorithm, LMMSE algorithm, and also introduced the interpolation methods of data channel estimation including the constant interpolation, linear interpolation, Gaussian interpolation, Sinc interpolation which are on the premise of pilot channel estimation, and respectively simulated the performance of bit error rate (BER) and mean square error (MSE) of the estimation algorithms and interpolation methods in specific circumstances and comprehensively analyzed and compared the effectiveness and feasibility of the algorithms; Then detailed analyzed the physical layer of 802.16e standard and LTE protocol, and designed the implementation of channel estimation algorithm adopted the LS and linear interpolation according to the pilot structure and concrete parameter of protocol; Simultaneously analyzed and optimized the implementation performance of channel estimation algorithm based on protocol which was implemented on the platform of CCS software combined the TMS320C6000 DSP characteristics of TI corporation, and good results were achieved.Finally, the work was summarized up and the ideas and vision for further work was brought.