Patent ID: 7796687
Filing Date: 2010-09-14
Classification: H04L

Abstract:
1. An enhanced reconditioning equalizer filter chain for multi-carrier signals to enhance the performance of any communication transmitter, an enhanced reconditioning equalizer filter chain for multi-carrier signals comprising: a peak reduction filter to produce a peak reduced main multi-carrier baseband signal; a first down converter to down convert a main multi-carrier baseband signal to produce a baseband representative of each individual carrier of the main multi-carrier baseband signal; a second down converter to down convert the peak reduced main multi-carrier baseband signal to produce a baseband representative of each individual carrier of the peak reduced main multi-carrier baseband signal; a reconditioning equalizer filter to re-condition and smoothen the baseband representative of each individual carrier of the main multi-carrier baseband signal using the baseband representative of each individual carrier of the peak reduced main multi-carrier baseband signal, wherein the reconditioning equalizer filter comprises: a first feedforward loop to inject a controlled in-band signal into the baseband representative of each individual carrier of the main multi-carrier baseband signal, comprising: a first gain element in a first feedforward loop to adjust the gain of the baseband representative of each individual carrier of the main multi-carrier baseband signal; a first delay element in a first feedforward loop to adjust the delay of the baseband representative of each individual carrier of the main multi-carrier baseband signal; a subtractor that subtracts the delay and gain adjusted baseband representative of each individual carrier of the main multi-carrier baseband signal and the baseband representative of each individual carrier of the peak reduced main multi-carrier baseband signal; a correlation function to correlate the baseband representative of each individual carrier of the main multi-carrier baseband signal and the result of the subtraction of the delay and gain adjusted baseband representative of each individual carrier of the main multi-carrier baseband signal and the baseband representative of each individual carrier of the peak reduced main multi-carrier baseband signal to calculate the amount of the delay and gain adjustment for the baseband representative of each individual carrier of the main multi-carder baseband signal; a digital FIR (or IIR) low pass filter with configurable coefficients to filter the result of the subtraction of the delay and gain adjusted baseband representative of each individual carrier of the main multi-carrier baseband signal and the baseband representative of each individual carrier of the peak reduced main multi-carrier baseband signal; a second gain element to adjust the gain of the low pass filtered subtraction of the delay and gain adjusted baseband representative of each individual carrier of the main multi-carrier baseband signal and the baseband representative of each individual carrier of the peak reduced main multi-carrier baseband signal; a delay and gain adjustment element to adjust the delay and gain of the baseband representative of each individual carrier of the main multi-carrier baseband signal; a summer to add the delay and gain adjusted baseband representative of each individual carrier of the main multi-carrier baseband signal and the gain adjusted low pass filtered subtraction of the baseband representative of each individual carrier of the peak reduced main multi-carrier baseband signal and the delay and gain adjusted baseband representative of each individual carrier of the main multi-carrier baseband signal; a third gain element to adjust the gain of the sum of the delay and gain adjusted baseband representative of each individual carder of the main multi-carrier baseband signal and gain adjusted low pass filtered subtraction of the baseband representative of each individual carrier of the peak reduced main multi-carrier baseband signal and the delay and gain adjusted baseband representative of each individual carrier of the main multi-carrier baseband signal; a delay equalizer to delay equalize the reconditioned and smoothened baseband representative of each individual carrier of the main multi-carrier baseband signal; an upconverter that up converts the reconditioned and smoothened baseband representative of each individual carrier of the main multi-carrier baseband signal to its baseband signal frequency; a summer that sums all of the up converted, reconditioned, smoothened and delay equalized baseband representatives of each individual carrier of the main multi-carrier baseband signal to produce the reconditioned and smoothened main multi-carrier baseband signal; a controller that uses the baseband representative of each individual carrier of the main multi-carrier baseband signal, the output of the enhanced reconditioning equalizer filter for the baseband representative of each individual carrier of the main multi-carrier baseband signal, and external information to provide control signal to various delay and gain functions as well as the peak reduction filter, FIR low pass filter and the correlation function.