Ofdm Wireless Communication System Are 27 Than Suppression Technology Research

Orthogonal Frequency Division Multiplexing (OFDM) is a typical parallel multi carrier transmission technology, it uses mutually orthogonal sub-carriers to transmit information, so this technology has very high spectrum efficiency and good anti-multipath capability and suitable for high speed and multimedia data transmission. But the high peak-to-average power ratio (PAPR) problem is the bottleneck in the development of OFDM technology, PAPR reduction is a difficulty and key problem in the OFDM system.Aiming at the problem of PAPR, we analysis some commonly used algorithms in the OFDM signal PAPR reduction, two new ways are proposed based on the existing algorithms which is suitable for wideband wireless communication system, the main contents as follows:1. Firstly, we introduce the principle of OFDM, key technology and its advantages and disadvantages, and then put forward the OFDM PAPR problem and its origin.2. The PAPR reduction techniques in the OFDM system were studied. Then we analyzed some main algorithms for PAPR reduction, such as Clipping, Selective Mapping (SLM), Partial Transmit Sequence(PTS), finally the performance of these algorithms were simulated by MATLAB.3. For solving the problem of in-band distortion and out-band radiation of Clipping and high computation complexity of SLM and PTS, a new algorithm for PAPR suppression was proposed, that is Iterative FFT algorithm, which is very simple, without any additional modules, the simulation result is notable.4. In order to solving the problem of the high computational complexity of PTS, a new PTS algorithm based on the genetic algorithm was proposed, called PTS-GE algorithm, which is not restricted by phase factor number and sub-block number of PTS algorithm, so it has strong versatility.