Patent ID: 7729420
Filing Date: 2010-06-01
Classification: H04L

Abstract:
1. A reconditioning equalizer filter to condition and smoothen a main baseband signal to improve the performance of a transmit path, for use with Orthogonal Frequency Division Multiplexing (OFDM) and Non-OFDM signals to enhance the performance of any communication transmitter, in any wireless cellular, Personal Communication System (PCS), wireless Local Area Network and Wireless Wide Area Network (LAN/WAN), WiMax, Video and Audio Wireless Broadcasting, line of sight microwave, military, optical, satellite communication systems and any other wireless applications, the reconditioning equalizer filter comprising: a peak reduction filter that performs peak reduction filtering to produce a peak reduced main baseband signal; a feedforward loop that injects a controlled in band and out of band baseband signal into the main baseband signal; a gain element that adjusts the gain of the main baseband signal; a delay element that adjusts the delay of the main baseband signal; a second gain element that adjusts the gain of sum of the delay and gain adjusted main baseband signal and the injected baseband signal; a controller that uses the main baseband signal, the output of reconditioning equalizer filter, and external information to provide control signals to various delay and gain functions as well as the peak reduction filter, the correlation function and a convolution filter; a digital baseband convolution filter which uses a Discrete Fourier Transform (DFT) or Fast Fourier Transform (FFT) of the result of the subtraction of the delay and gain adjusted main baseband signal and the peak reduced main baseband signal as a first input and the normalized Discrete Fourier Transform (DFT) or Fast Fourier Transform (FFT) of the delay and gain adjusted main baseband signal as a second input to its multiplier, wherein the digital baseband convolution filter comprising: a DFT or FFT function that converts the time domain subtraction of the delay and gain adjusted main baseband signal and the peak reduced main baseband signal to frequency domain; a DFT or FFT function that converts the time domain delay and gain adjusted main baseband signal to frequency domain; a normalization function that normalizes the frequency components of the delay and gain adjusted main baseband signal produced by DFT (or FFT) of the delay and gain adjusted main baseband signal to predefined values based on defined or configured thresholds; a multiplier that multiplies the normalized DFT or FFT of the delay and gain adjusted main baseband signal and DFT (or FFT) of the subtraction of the delay and gain adjusted main baseband signal and the peak reduced main baseband signal; an IDFT or IFFT function that converts the output of a multiplier that multiplies the normalized DFT (or FFT) of the delay and gain adjusted main baseband signal and DFT (or FFT) of the subtraction of the delay and gain adjusted main baseband signal and the peak reduced main baseband signal to time domain.