ABSTRACT
Peak-to-average power ratio (PAR) is the most commonly used metric to assess the dynamic range of symbol (also called block)-based signals. The objectives of PAR reduction are
1. To decrease the amount of power required to transmit a signal 2. To reduce the signal’s sensitivity to the system nonlinearities 3. To reduce the physical size requirements of the analog components thanks to the smaller dynamic
range
A similar metric known as instantaneous-to-average power ratio (IAR) is also frequently used and is preferred for signals that do not have distinct separable symbols. PAR and IAR are important proxy metrics for power efficiency because they dictate the ratio between the peak power, which the transmission power amplifier (PA) must accommodate, and the average transmit power. This peak PA power has a one-to-one relationship with the amount of power consumed by the PA. Thus, it is very important to limit the PAR or IAR of a signal by implementing clever methods, which have the effect of increasing the power efficiency.
