Development And Performance Analysis Of CDMA Wireless Wideband Small-power Repeater

With rapid inceasing of the mobile phone users and the construction of the various building and underground facilities, subscribers have an increasing demand for the communication coverage ability. Although there are more feasible solutions for the indoor coverage (such as microcell technique), but for applications requiring no further capacity, a small-power repeater is the cheapest and simplest solution for communication coverage extending. Firstly, the significance of the CDMA repeater development is summarized in this paper, and then the development and performance analysis process of the CDMA wireless wideband small-power repeater which is applied to indoor coverage of CDMA mobile communication network is described in detail. This paper first illuminates the structure of the CDMA wireless wideband small-power repeater and its technical requirements. Give the repeater's downlink for an example, its hardware design, chain circuit budget, elements choosing and optimization simulation are described. The problems encountered in circuit troubleshooting and the solutions are enumerated here and the test result of the whole repeater is also presented. In order to scale the distortion characteristic of the signal outputed by the repeater excited by CDMA signal with nonconstant envelop, the parameters used to describe the nonlinear characteristic of the repeater are defined, calculated and analyzed by utilizing the complex envelop, time/frequency domain analysis and MATLAB simulation techniques synthetically. By comparison, the index of spurious emission in adjacent channel and dual-tone intermodulation attenuation are more rigorous for the requirement of the repeater's linear performance. Finally, the engineering application problem of the CDMA repeater is studied. The work parameters of repeater are analyzed and calculated on the basis of link balance principle. The influences between the repeater and the 900MHz GSM and CDMA system are discussed. And the problem of antenna's usage is presented at the end of the paper.