In wireless transceivers, down converters transform a radio frequency (RF) signal into a baseband signal centered at the zero frequency. Similarly, up converters transform a baseband signal into an RF signal. Down conversion and up conversion have traditionally been performed in the analog domain. However, the next generation of wireless transceivers perform down conversion and/or up conversion in the digital domain. For example, a receiver may employ RF sampling, in which the RF signal is directly sampled with a high speed, high performance analog-to-digital converter (ADC) (e.g., a 14 bit, 3 giga-sample-per-second ADC). The use of RF sampling allows such receivers to employ digital down-converters that avoid mixers in the RF/analog domain. In a digital down-converter, mixing is implemented using digital multiplication circuitry.