Research On Several Issues Related To 60GHz Millimeter Wave Short Range Communication

Under the condition of more and more less available spectrum resource and the trend of mulitigigabit wireless data transmition, 60GHz technology gains more and more significant interest from researchers. And it becomes the most promising indoor wireless communication system in the future. This paper mainly pays attention to the study on the propagation characteristic of 60GHz channel and the probable system scheme.This paper makes an investigation on the propagation characteristic of 60GHz channel. It gives the attenuation characteristic of signal at 60GHz, including gas attenuation and material attenuation. By Introducing ray tracing method, a simulation of propagation characteristic of 60GHz channel is carried out in a small empty room. From the simulation we obtain the antenna effect to the propagation characteristic. The results shows that using circular polarized and directional antenna in 60GHz system can reduce the multipath effect significantly.The probable 60GHz communication system scheme is also studied in this paper, including the scheme of carrier modulation, the modulation, the optimum beam width, the receiver scheme and so on. Considering the cost and complexity, an impulse radio system is proposed, together with binary phase shift key(BPSK) modulation which can save transmit power and guarantee a moderate anti-nonlinearity. By analyzing the the distribution of the arrival of angle of rays in ray tracing simulation, an optimum beam width is presented. Furthermore, basing on the characteristic of impulse radio system, the monobit sampling receiver scheme is proved to be feasible in 60GHz communication system. It reveals that the monobit sampling scheme has a litter SNR loss compared to full resolution matched filter scheme in both additive white Gaussian noise(AWGN) channel and 60GHz channel. An analysis of the performance of the proposed 60GHz communication system scheme in this paper is presented at the end. It illustrates the maximum data rate of the system scheme and the probable methods of increasing the data rate.Aiming at the system request of carrier suppression, a carrier-suppressed balance BPSK modulator was proposed. The principle of modulator is to split one local oscillator signal into two balance channels with 180°out-of-phase through a microstrip power splitter, then both signals are multiplied with two positive pulses respectively and at last two modulation signals converges at a single channel in the microstrip combiner. Leakage of carrier wave can be significantly suppressed because it is counteracted in the process of modulation. The performance of the modulator is also analyzed including the carrier suppression and Error Vector Magnitude(EVM). Otherwise, the factor of impact the modulator performance and some design rules are presented.