Advantages and disadvantages of TD SCDMA

Compared with WCDMA and CDMA2000, TD-SCDMA has the following characteristics and advantages:

(1) High spectrum Utilization: TD-SCDMA uses TDD method and CDMA and TDMA multiple access technology, it is easy to set up and downlink link conversion points for different types of service in transmission, so the total spectrum efficiency can be higher.

(2) Support multiple communication interfaces: TD-SCDMA simultaneously satisfies IUB, A, Gb, Iu, iur a variety of interface requirements, base station subsystem can be used as 2G and 2.5G GSM base station expansion, but also as the 3G network Base station subsystem, can take into account the current needs and future long-term development.

(3) Strong spectrum Flexibility: TD-SCDMA third-generation mobile communication systems have a strong spectrum flexibility, only a single 1.6M band can provide 2M of 3G business requirements, and very suitable for asymmetric business transmission.

(4) Stable performance of the system: TD-SCDMA transceiver in the same frequency band, uplink and downlink wireless environment consistency is good, more suitable for the use of emerging "smart antenna" technology, using CDMA and TDMA combination of multiple access, more conducive to the adoption of joint detection technology, these technologies can reduce interference, Improve the performance of the system stability.

(5) compatible with the traditional system: TD-SCDMA support the existing coverage structure, signaling protocol can be back-compatible, the network does not need to introduce a new call mode, can realize from the existing communication system to the next generation of mobile communication system smooth transition. (Computer science)

(6) Low cost of system equipment: TD-SCDMA work at the same frequency, the symmetrical wave propagation characteristics make it easy to use smart antenna and other new technologies, which can also achieve the goal of reducing costs; In the wireless base station, TD-SCDMA equipment costs are relatively low.

(7) To support the switching between the traditional systems: TD-SCDMA Technology supports multi-carrier direct spread spectrum system, can reuse the existing framework equipment, community planning, operating system, billing system, in all environments to support symmetric or asymmetric data rates.

Of course, compared with the first two standards, especially with WCDMA, TD-SCDMA also has "immature" place. For example, in the use of CDMA technology, TD-SCDMA to be compatible with the GSM community, community multiplexing coefficient of 3, reducing the frequency spectrum utilization. Because TD-SCDMA band width is narrow, it can not make full use of multipath, reduce the system efficiency and realize soft switching and soft capacity is more difficult. In addition, the TD-SCDMA system to be refined to determine, the cell to maintain synchronization between the timing system requirements high. And WCDMA does not need the synchronization between the cells, can adapt to indoor, outdoor, and even the subway and other environmental applications. In addition, WCDMA support for mobility more high-quality, suitable for macro-honeycomb, honeycomb, micro-cellular network, and TD-SCDMA only for micro-cellular, high-speed mobile support is also poor.