4.1. Introduction

A receiver can be implemented in terms of different architectures, such as superheterodyne, direct conversion, low IF, or band-pass sampling, as discussed in the previous chapter. No matter which architecture is employed, the receiver should possess a well-defined function and performance. This means that the mobile station receivers operating in a wireless system may be different in their architectures, but they must have many common characteristics to achieve the unique performance specified in the wireless communication system standards.

As we know, there are two kinds of duplex systems, full-duplex and half-duplex systems, used in the different wireless communication systems. The CDMA, WCDMA, and AMPS systems are full-duplex systems. In these systems, the receiver and the transmitter of either the mobile stations or the base stations are operating simultaneously, but they operate in different frequency bands. Other wireless communication systems, such as the GSM, GPRS, TDMA, and PHS systems, are the half-duplex system. In the half-duplex system, the receiver is running in time slots different from those that the transmitter is operating in, but they may use the same operation frequency. It is apparent that in the full-duplex system the transmission of the transmitter is a strong interference source to the receiver since the transmission power at the receiver antenna port can be 120 dB or even 130 dB stronger than the desired reception signal, but the transmission frequency is only tens of MHz away from that of the reception signal. The corresponding receiver must be able to work...