Research And Implementation Of OFDM Synchronization Based On TMS320VC5502

Orthogonal frequency division multiplexing (OFDM) technology, with high transmission speed, anti-interference ability and high bandwidth efficiency advantages, can effectively undermine the existence of a variety of power-line channel noise, attenuation and multipath propagation, and other adverse effects. It is effective modulation of power line carrier communication. OFDM system is highly sensitive to synchronization error, therefore, the synchronization problem is key technologies of whole system to achieveis the reliability.In this paper, the hardware DSP chip TMS320VC5502 carriers, around the OFDM system synchronization issues, analysis of what the OFDM system in the synchronous cases did not meet the frequency deviation, symbol timing clock skew deviation and sample performance of the whole system, on this basis, determining OFDM synchronization algorithm performance indicators. After reference and comparison of some existing synchronization program, an improved training sequence is proposed for the power line carrier communication system which based on a synchronized program. Design a reverse structure with training sequence, which is a good correlation in the time domain and frequency domain, through the MATLAB program related to the synchronization algorithm and the simulation AGC algorithms it can achieve accurate symbol timing synchronization and synchronous sampling.This paper is designed based on TMS320VC5502 hardware systems, and with the help of PROTELL99 mapping software, the completion of the power conversion circuit, A/D data sampling circuit and JTAG interface circuit design, this hardware platform which to achieve synchronization of power line carrier communication program. The paper with DSP software development platform CCS3.3, designed the A/D sampling data reception, coarse synchronization and fine timing synchronization, as well as the sampling clock correction and FFT modules, by writing C programs will be achieved on the TMS320VC5502 chip based on the power line channel synchronization scheme for OFDM systems. Experimental results show that this program header overhead is small, with simple operation, maintaining good reliability which in bad channel conditions, can achieve high-speed data transmission.