The Study Of UWA Communication Algorithms Based-on OMAP-L137

Underwater acoustic communication is very important research branch in underwater acoustic field, which is initially driven up by the military, and now has gradually developed into the civil field, such as marine exploration, resource development, voice communications etc. Underwater acoustic communication must face the complexity of underwater acoustic communication channel marine environment, the main unfavorable factors are multi-path effect, sea noise and the limited bandwidth, has brought acoustic communication difficulties.To overcome the negative effects in underwater acoustic channel. Orthogonal Frequ-ency Division Multiplexing is commonly referred to as OFDM, this technology has become a new focus on underwater communication research because of its own characteristics. OFDM has high bandwidth efficiency, this is an outstanding advantage where the available bandwidth is limited in underwater acoustic communications. And this technology can according to the characteristics of the channel, flexibly modulates the information to available sub-carriers with smaller interference, so the quality of communication would be improved. The technology of cyclic prefix in OFDM can effectively resist the inter-symbol interference caused by multi-path, solve an inherent problem in underwater acoustic communication. And this technology can fast achieve modulation and demodulation by using the IFFT and FFT, it is easy for system design.This system is implemented on the hardware platform based on OMAP-L137. Using McASP to sending and receiving data, the used of EDMA can reduce the usage of CPU. Though configurating AIC3254 to achieve the data conversion of digital to analog. The DSP core in OMAP-L137 is clocked at 300MHz, with a high processing speed, and can be flexible or fixed-point floating-point operations, to meet the requirements of OFDM encoding and decoding operation. After configuration and debugging has operated on the data path on the bottom hardware, this paper finishes the joint debugging of sending and receiving based on technology of OFDM, the requirement of communication has realized successfully.