一、专用无线通信技术的现状及同频传输地点分集技术的引入　　随着数字技术的发展，数字集群通信标准如ＴＥＴＲＡ等相继出现并不断完善，毋用置疑，数学化必将成为无线通信发展的趋势和潮流。然而，传统的模拟通信网尽管存在着干扰大、频谱利用率不高、保密性差等缺陷，但却 First, the status of private wireless communications technology and the introduction of the same frequency transmission site diversity technology With the development of digital technology, digital trunking communications standards such as TETRA appeared one after another and continue to improve, without doubt, mathematicization will become the development of wireless communications Trend and trend. However, although the traditional analog communication network has the defects of large interference, low spectrum utilization and poor privacy,