Patent ID: 7142831

Claim:
A wireless Crest Factor reduction and amplitude pre-distortion circuit for use with multi-carrier signals in a wireless communication system to enhance the linearity and performance of the amplifier, in wireless cellular, PCS, wireless LAN, line of sight microwave, military, and satellite communication systems, the Crest Factor reduction and amplitude pre-distortion circuit comprising: a multi-carrier receiver for the Crest Factor reduction and amplitude pre-distortion of IF or RF input signal to an amplifier, wherein the input signal is baseband then the multi-carrier receiver is bypassed; an envelope detector that produces the envelope of the feedback multi-carrier signal from the output of the amplifier; a digital signal processing function to reduce the Crest Factor of the multi-carrier input signal; a digital signal processing function to limit or clip the amplitude of the multi-carrier signal; a digital signal processing function that converts the amplitude clipped or limited multi-carrier baseband to baseband representative of individual carrier signals; a digital signal processing function that filters the baseband representative of individual carrier baseband signals to remove unwanted signal produced due to clipping or limiting the multi-carrier signal amplitude; a digital signal processing function that up converts the filtered baseband representative of each carrier to its original baseband frequency; a digital signal processing function that pre-distorts the Crest Factor reduced multi-carrier signal using a look up table; a multi-carrier transmitter that prepares the Crest Factor reduced and pre-distorted multi-carrier signal for delivery to an multi-carrier amplifier; a digital signal processing function that adaptively updates an amplitude pre-distortion look up table; a digital signal processing function that gain and phase adjusts the inputs to an amplitude pre-distortion adaptation algorithm.