Study On The Physical Layer Modulation And Demodulation Algorithm Based On EDGE System

EDGE technology has been adopted as the 2G technology to 3G technology transition program, because it can use the existing network equipment and resources of GSM system to enable operators to offer personal multimedia services to mobile users, While it is still used by most of the conventional mobile users. In the radio channel, because of the NLOS of radio waves It will produce ISI, which affects the communication quality. The role of equalization is to effectively eliminate ISI. After making a brief introduaction of the main technology in EDGE physical layer, this paper describes reduced-state equalization algorithm, channel estimation algorithms and principle and design of prefilter, and make physical layer simulation of the EDGE system which based on MCS-5.The section of Balancing Algorithm described MLSE, DDFSE and RSSE in detail. If MMSE algorithm is applied to the EDGE system, it will bring huge amount of computation. This cannot be realized in existing DSP. So we introduced two kinds of balanced algorithms to reduce the States Number: DDFSE and RSSE. These two algorithms reduced the complexity of the operation by reducing the State Number. In TU channel model, make simulation of these two equalization algorithm, comparing the advantages and disadvantages of the two equalization algorithms by simulation. Channel estimation algorithm part details of the common autocorrelation, LS and LMS three kinds of channel estimation algorithm theory and implementation process. We simulated them with MATLAB, and analyzed the results. The section of Pre-filtering introduced the principle pre-filtering and the realization process of LP prefilter. In all the pre-filtering algorithm, the complexity of LP algorithm is the lowest so that it is the easiest to be realized. Therefore, this article adopted the pre-filter based on LP Algorithm. Simulation results show that the pre-filter equalization algorithm to improve the performance has a significant effect.Based on the above theory, this paper presents the overall scheme of receiving the downlink and its implementation process. By EDGE signal off-line test, the results show that performance of the system met the requirements of the agreement, the validity and feasibility of the receiving program.