Investigation On Full-duplex 60-GHz-band Radio-over-fiber System

In the past time, the technique of RoF(radio over fiber) which came from millimeter-wave communication was aimed at increasing the efficient utilization of wireless frequency spectrum resources and reducing the scale of remote modules. Now, with the development of the RoF technique research, the applications of RoF have expanded to the fields of millimeter-wave communication, intelligent road vehicle communication and wideband wireless access network, etc. In millimeter-wave wireless communication RoF system, many base stations are connected with one central station by fibers. The system is required to produce low phase noise wireless signals and conquer the dispersion effect in fiber transmission. We evaluate the millimeter-wave wireless communication RoF system from consideration of techniques and cost two sides: comparing the different ways of millimeter-wave produce and the different methods of transmission in techniques side, and considering reducing the base station cost in cost side.The main contents of this thesis are as follows:(1) Give a summarization of the development of millimeter wave communication and applications of RoF system.(2) Discuss about the key technologies and the existent problems of RoF system. Based on this, the comparison of four different kinds of RoF systems with their advantages and disadvantages are presented.(3) Aim at the dispersion problem of millimeter-wave band optical signals and the complexity of the structure of base station in RoF at present. A RoF system employing a 60GHz electro-absorption transceiver (EAT) together with a dual-lightwave technique is reported, by realizing single- and dual- wavelength modulation in downlink and uplink respectively, a base station with detection, modulation and frequency up/down-conversion functions is obtained. On the one hand, the frequency conversion between millimeter-wave and intermediate frequency is realized. This makes the transportation of intermediate frequency band optical signals in links, and conquers the problem of dispersion. On the other hand, the transformation from EAT to electro-absorption transceiver/mixer (EATX) is realized. This avoids making the special EATX device and leaving out the RF frequency conversion equipment, as a result, the base station structure is simplified. (4) By stimulating the system, the transmission of 60GHz-band subcarrier multiplexed 2Gbit/s and 500Mbit/s pseudorandom return-zero formatted data in downlink and uplink respectively is accomplished.(5) Introduce the performance parameters of RoF system and the techniques to improve them.At last, we sum up the whole work,and prospect the future work.