60 GHz Millimeter-wave Wireless Communication System : Modulation And Capacity Research

60 GHz millmeter-wave wireless communication system is identified as the most promising wireless communication technology in the next decade, because of its 5 - 7 GHz bandwidth and 10W transmission power. 60 GHz is on the category of millimeter-wave. The Electromagnetic wave, frequency band range from 30GHz to 300GHz, belongs to millimeter-wave. Because it has the advantages, such as short wavelengths, wide frequency band, and the effectively solution of the high-speed broadband wireless access problems, the millimeter-wave has broad application prospect in short-range wireless communication.At present, the theoretical analysis of capacity and performance of the 60GHz system is basically blank in the global scope. In order to adapt to the needs of the development of the era of telecommunication, the study on this frequency communications system is of great significance.It can be seen that within a period of the future time, the study of 60GHz wireless communication system which can realize ultra-high speed data rate will continue to be hot spot of the wireless communication field.Modulate the 60GHz millimeter-wave wireless communications with M-ary phase shift keying (MPSK), M-ary pulse amplitude modulation(MPAM) and M-ary pulse position modulation(MPPM), the data transfer rate is very high, so it has very important directive functions on the development of 60GHz application products and network design. So It will promote the realization of various of 60GHz's applications of great stimulative effect.With the research of the key technologys in 60GHz wireless communication system become increasingly mature, and the various product applications available soon, people need to master the system capacity and performance of the 60GHz wireless communication system and various factors and key technology that impact the system capacity and properties, increasingly.The research work is start of the theory analysis and derivation that according to discrete memoryless channel, discrete input, continuous output channel and continuous channel's capacity calculation formulas. Deduct the Relations function between Shannon capacity and transmission distance.Secondly, deduce the functions of channel capacity(C) to signal to noise ratio (SNR) and channel capacity(C) to the communication distance with the theory of MPSK and the mathematical model of gaussian channel. Utilize the Matlab, it shows the relation curves of C to SNR, C to Communication distance with different M-arys.Thirdly, deduce the functions of C to signal SNR and C to the communication distance with the theory of MPPK, MPAM and the mathematical model of gaussian channel.In the end: compare the channel capacity(C) of MPSK with MPAM, the conclusion is that the channel capacity of PSK is larger than PAM when the SNR is -20dB and 20dB; compare the channel capacity(C) of MPPM with MPAM, the conclusion is that when the SNR is high, the channel capacity(C) of PPM is better than PAM; when the (SNR) is low, the channel capacity(C) of PAM is better than PPM. In short distance, choose the high ray(lager than 8), channel capacity(C) of PPM is better than PAM.In the research process, the paper takes the Federal Communications Commission power constraints for the 60GHz wireless communication system into consideration. The result shows that, the capacity of 60GHz wireless communication over AWGN channels is a function of communication distance and signal to noise ratio and the system is suitable for short distance communication,the rate can reach to Gbitps. The channel capacity(C) of PSK is better than PAM, when we choose the low ary, the channel capacity(C) of PAM is better than PPM.