Performance Of FH Communication System Over A Nakagami Fading Channel

Hopping frequency (FH) is the important technology of spread spectrum communication, which is widely applied in anti-jamming communication. The frequency hopping (FH) communication is widely applied in modern military and civil communications because of its advantages such as anti-jamming, anti-fade, anti-capturing, and multi-access networking etc. Radio channel modeling is important to design and research of the mobile communication system. The thesis investigates and compares radio channel modelings. And we present a comprehensive analysis for the performance of the FH communication system over Nakagami fading channels.First, the thesis describes the principle and scheme of FH. Then the paper deeply researches radio mobile channels, especially the characteristics of multipath propagation. Above all, we find that we can alter the parameter of Nakagami-m fading channels to other fadings.To extend the investigation of the Nakagami-m fading channels to FH communication system, we summarize the Nakagami-m channel simulation theory, Nakagami fading parameter estimation theory and the Nakagami channel simulation algorithm. On this condition, we investigate five indicators to evaluate the validity of the Nakagami simulation channel. They are fading parameter consistency, amplitude probability density function consistency, phase probability density function consistency, squared-envelope autocorrelation function consistency and normalized quadrature component autocorrelation functions consistency. And the thesis investigates and compares two typical methods of generating Nakagami-m random variables i.e. Brute-force method and inverse transform method with each other by the complexity of implementing the algorithm as well as the efficiency of programming. The results indicate that inverse transform method is suited for all values of fading parameter m in the Nakagami-m channel simulation.The thesis focuses on the design and realization of FH communication system simulation platform on the basis of Nakagami-m fading channels. The simulation platform for FH systems employing RS code and Nakagami-m channel is set up, and lots of experiments are carried out based on the platforms. Our analysis and simulation results show that the fading parameter m and the number of user influence the bit error rate (BER) of the FH communication system employing Nakagami-m channel. The bit error rate (BER) is improved significantly in the same number of user when the fading parameter m increase. The BER of the system employing Nakagami-m channel is close to the BER of the system employing AWGN channel in single-user situation when m is ten.