The choice of receiver architecture is dictated mainly by six high-level parameters: performance, implementation complexity, size, number of external components, power consumption, and cost. The relative importance of each of these parameters, albeit some go hand and hand, has varied over the years depending on IC technology and the underlying wireless application. From a signal processing perspective, the receiver can be thought of as a system divided into the following subsystems: antenna, analog front-end, analog intermediate frequency (IF) and baseband, data conversion, frequency generation, and digital baseband. In the receiver, the antenna is a transducer system that transfers electromagnetic energy into electrical or magnetic energy. The antenna's gain, directivity, frequency bands of operation, and the antenna's form factor are some of the key parameters defining its performance. The analog front-end is comprised of filters, amplifiers, switches, and mixers. It plays a key role in setting the receiver's sensitivity and linearity. The analog baseband is also comprised of filters and gain stages. The channel selectivity and interference mitigation are predominantly set by the analog low-pass or IF filters. The impact of phase noise on the receiver performance becomes apparent at this stage. The analog baseband is followed by the data conversion subsystem. Two types of analog-to-digital conversion schemes were discussed: Nyquist converters, and oversampling converters. The parameters of interest, at this stage, range from converter resolution and sampling rate to converter nonlinearity, and jitter performance. The frequency conversion block is designed with a certain frequency plan in mind to facilitate the down-conversion (or up-conversion) of signals from radio frequency (RF) to baseband or RF to IF. The last block is the digital portion of the receiver where the signal after analog-to-digital conversion is demodulated and synchronization is performed. At this stage, the signal may undergo further equalization and decoding before the data packets are sent to MAC and higher link layers.