The Implementation Of Digital Processing Module In Differential Frequency Hopping Radio

Differential Frequency Hopping (DFH) technique is new communicationtechnique which is brought forward recently. Because DFH has excellent capability inanti-interfering, anti-fading, reliability, secret, it is becoming the focus of militarycommunication. That the DHF pattern is based on ergodic process of a directed graphmakes DHF has good randomicity and can assist code-error detecting. The transmitterof DHF uses DDS to synthesize frequency. The receiver is based on software radioscheme which can simplify the design of hardware circuit.With the rapid development of VLSI, ultra-speed DSP is designed, which makessoftware ratio be implemented at present. The emphases of this paper are below:apply a series of signal-processing method on receiving signal to identify frequency,decode data,write program on TMS320C6201 DSP and make it running.This paper emphasizes on the method of window synchronization of DHF,establishes the corresponding theory, and gives detailed data and charts. Based on thetheory, this paper projects the window synchronization arithmetic and realizes it inTMS320C6201 DSP. The tests indicate that the arithmetic has high-precision, verylow pseudo-synchronization. In order to improve the result, the sample data areprocessed with window function. The classic 16-bit FFT program is rewritten toexpand the precision and avoids overflow. Based on analysis of key hardware circuitand software, this paper provides the online method and principle. The digital modulesuccessfully uses expansion-precision FFT program to identify frequency ,accomplish the decoding work.The core codes of digital module are written with assemble language andoptimized. Also, it can manage memory efficiently. The tests prove it to be successfuland meet the design requirement.