Design And Implementation Of TD-SCDMA Air Interface Protocol Stack Based On DSP

The third Generation of wireless communication technology is coming at the monment. In the field of communications technology CDMA is considered as mainstream technology of 3G. The ITU identified three wireless interface standard, namely, CDMA2000, WCDMA, TD-SCDMA. TD-SCDMA, the 3G protocol is one of three standard protocols, as a result of using division duplex, uplink and downlink channel characteristics consistent in TD-SCDMA system, therefore, the uplink and downlink channel features consistent basically and that the base station estimated characteristics of upstream and downstream channel according to the received signal is more easier. In addition, TD-SCDMA which use smart antenna technology has inherent advantages, while the smart antenna technology has bring in advantages of the SDMA that can reduce interference between users and improve spectrum utilization. In this article the air interface (Uu) based on TD-SCDMA communications technology protocol has been analysised detailed and, based on the analysis of air interface communications the hardware and software systems are builded.In the core of TMS320DM642 the hardware system platform of air interface protocol is builded, in the hardware platform the network driver is transplanted in, and LwlP (TCP/IP) protocol stack is ported to the hardware in the core of DM642. Then on the hardware platform, serial port driver, key driver, and LED lights drives are moved in. Hardware platform, as the integrated data processing center of air interface protocol stack is responsible for data processing and extraction, which require large amounts of computation.System software modules include three components: software module of RRC layer, software module of RLC layer and software module of MAC layer. Software modules of air interface protocol stack communicate with communication primitive.In addition in the air interface protocol the static location update strategy are improved, that add the timer mechanism, which could saves system resources. After the test, the system functions of air interface have come true.