A wide-band direct conversion receiver for WCDMA applications

Current digital mobile communications systems, such as GSM, are specified for voice-band applications. The channel bandwidths up to some hundreds of kHz limit data transfer to low bit rates, in applications such as electronic mail. The 3rd-generation global mobile system is in development under the International Telecommunications Union (ITU). It will be capable of transmitting various services from voice to multimedia with different quality requirements for single or multiple users in the same frequency band. Data rates from 8 to 384 kb/s in wide-area applications, and even 2 Mb/s indoors, will be possible. The flexibility comes from use of the wideband code division multiple access (WCDMA) scheme in the radio interface.