WCDMA Technical Standards Development Trends

WCDMA was originated by standardization organizations and manufacturers in European countries and Japan. WCDMA inherits the high standardization and openness of GSM, and its standardization progresses smoothly. WCDMA is the third generation mobile communication standard developed by 3GPP, with the GSM MAP as its core and UTRAN (UMTS Terrestrial Radio Access Network) as its wireless interface. Using the chip rate of 3.84 Mbps, it provides data transmission rate up to 14.4 Mbps within 5 MHz bandwidth.

The WCDMA technology has the following characteristics:

1. Supporting both asynchronous and synchronous BTSs, for easy and flexible networking 
2. Using QPSK modulation mode (the HSDPA services also use the 16QAM modulation mode) 
3. Using pilot assisted coherent demodulation 
4. Accommodating transmission of multiple rates, and implementing multi-rate and multimedia services by changing the spread spectrum ratio and using multi-mode concurrent transmission 
5. Rapid and efficient power control of uplink/downlink greatly reduces multiple access interference of the system, but increases the system capacity while reducing the transmission power. 
6. The core network is evolving based on the GSM/GPRS network, and maintains compatibility with the GSM/GPRS network. 
7. Supporting soft handover and softer handover, with three handover modes, inter-sector soft handover, inter-cell soft handover, and inter-carrier hard handover