gsm知识学习（GSM knowledge learning）.docVIP

gsm知识学习（GSM knowledge learning） GSM knowledge learning summary A base station, the minimum acceptable c/i (according to GSM index is c/i = 9dB) ? in the same environment, the Irish capacity of CDMA is limited to the maximum transmit power of the user unit GSM needs 200 base stations can cover 2 1000km share, and only 45 in CDMA and GSM base station. Every sector 42 slots (44 slot 95%), this is not practical, because it requires at least 8% slots for control. Even so, CDMA will base 80% less than GSM, increased and each CDMA sector is only 55%.gsm cell radius of maximum capacity with the actual traffic channel and narrow, for every square kilometer of 20 actual traffic channel, the maximum load is 50% CDMA, and each base station can support up to 2. 20km share on the other hand, when the gap is greater than 14 voice (subject to c/i = 14dB) the GSM base station can provide acceptable voice quality, which enables service providers to share 2 of the range of 6km. capacity In the limited spectrum, and expensive. An effective use of air interface spectrum can support many users in the same bandwidth, increase the potential income from the number of users, while reducing the costs associated with frequency spectrum utilization rate of.Cdma is]10 times amps, high capacity is CDMA. In the high-speed mobile state, CDMA can provide 25 calls / sector /cdma channel, which has been included 35% soft handover. Each CDMA channel using 1.25mhz to send and receive spectrum. In wireless local loop or low-speed mobile applications, soft switching is less, if using high gain antenna, it can support more than 40 a call / sector /cdma channel. - CDMA, GSM, amps capacity can be drawn from the comparison of 10MHz and 30MHz in the occupied spectrum. If the conservative protection zone, the 10MHz spectrum can be assigned to the 3 CDMA channel, 30MHz channel can be assigned to 11 CDMA GSM or amps; no protection zone, this is the best case for them, such as table 3, are shown in Table 4. Table