Receiver architectures for GSM handsets

The GSM receiver is defined for the purposes of this paper as the system which takes a signal from the antenna (perhaps sharing some of the front-end circuits with the transmitter) and delivers a digital signal to the baseband electronics for subsequent demodulation. It is essential that the digitisation process is regarded as a key responsibility of the receiver itself because the proper partitioning of gain control and filtering between analogue and digital sections of the receiver is a fundamental requirement in a good design. This means that the RF engineer needs to augment his or her traditional role of designing filters, mixers, amplifiers etc. to include an intimate working knowledge of the digitisation process and also, to a lesser extent, the options available in digital signal processing. For this reason, the various digitisation options and the way these reflect on the receiver architecture are studied in some detail.