Enhancement and gradual progress of TD-SCDMA mobile communiation system
Time- Synchronous code division multiple access (TD-SCDMA) It is the time-division duplex (TDD) put forward by China The 3rd generation of mobile communication technical standard that modal, it is 3GPP a canonial important constituent element. TD-SCDMA has adopted a lot advanced wireless communication skills, code division multiple access of the horizontal hold, Smart antennas, jointly detecting, software radio, relay switching over and dynamic channel allocation technology,etc. [1 ] as above. TDD mode does not need symmetrical frequency band, it is assigned that Radio Resource RRs can be flexible in upper and lower row intervals, suitable for such an antisymmetrical business of data transmission, the increasingly in short today of wireless frequency band resource, become the focus of B3G/4G system research gradually. In China, frequency-division duplex (FDD) ,Including the code division multiple access of broadband (WCDMA) And CDMA2000 mode, get 90 MHz frequency bandwidth altogether, get the bandwidth of 155 MHz, reflects the energetical support of TD-SCDMA of Chinese Government by and TDD mode, and indicated its good development prospect. Compared with WCDMA and CDMA2000 system, TD-SCDMA has its technical advantages, but lack the commercial experience. In future gradual progress, TD-SCDMA and WCDMA had very good compatibility, this switched over and roamed and laid a good foundation among many systems for the future. Core network edition that 3GPP puts forward that TD-SCDMA and WCDMA used at the same time, such natural combination makes two kinds of systems can be supported and complementary on the future development path each other. From the viewpoint of commerce and investment, the core network only accounts for about 30% of investment of overall system, so, in gradual progress in future, the compatibility of TD-SCDMA and WCDMA is still focal points studied. Though the architecture with CDMA2000 system has greater differences, the expediency of universality and user of serving of communicating for the whole world, focus that become commerce with the compatibility of CDMA2000 system too and the technical research pays close attention to. Pieces of this look over full text