Versatile system for multimode, wireless communication receiver with ZIF and near-ZIF operations

Abstract

An architecture for a receiver component in a wireless communications system is disclosed—one that supports both zero intermediate frequency (ZIF) and near-zero intermediate frequency (NZIF) operation. The architecture provides a down-conversion segment, and a local oscillator segment operatively associated with the down-conversion segment. An analog-to-digital conversion (ADC) segment is adapted to receive signals from the down-conversion segment and introduce the signals into a digital intermediate frequency (DIF) construct. The DIF construct performs a DC offset compensation or DC residue filtering on NZIF-based signals, and droop or mismatch compensation. Image removal is performed on NZIF-based signals, and DC offset compensation is performed on ZIF-based signals. Compensated signals are amplified to some nominal or desired level, and interpolation filtering of the amplified signals is performed prior to transmission thereof.

1 . A wireless communications device, supporting both zero intermediate frequency (ZIF) and near-zero intermediate frequency (NZIF) operation, the device comprising:
 a down-conversion segment;   a programmable synthesizer component operatively associated with a local oscillator segment;   the local oscillator segment operatively associated with the down-conversion segment;   an analog-to-digital conversion (ADC) segment adapted to receive signals from the down-conversion segment;   a digital intermediate frequency construct adapted to receive digital signals from the ADC segment; and   a digital to analog segment adapted to receive digital signals from the digital intermediate frequency construct.   
   
   
       2 . The device of  claim 1 , wherein the wireless communications device supports Wideband Code Division Multiple Access (WCDMA) operation mode. 
   
   
       3 . The device of  claim 1 , wherein the wireless communications device supports Global System for Mobile communications (GSM) operation mode. 
   
   
       4 . The device of  claim 1 , wherein the wireless communications device supports both Wideband Code Division Multiple Access (WCDMA) and Global System for Mobile communications (GSM) operation modes. 
   
   
       5 . The device of  claim 1 , wherein the down conversion segment comprises a demodulation element having the local oscillator segment operatively associated therewith. 
   
   
       6 . The device of  claim 1 , wherein the reconfigurable digital intermediate frequency construct comprises:
 an analog DC offset compensation element;   a digital mixer element;   a channel filtering element;   a digital DC offset compensation element; and   a variable gain amplification element.   
   
   
       7 . The device of  claim 6 , wherein the digital mixer element is driven by an oscillator element. 
   
   
       8 . The device of  claim 6 , wherein the digital mixer element is bypassed or disabled during ZIF operation. 
   
   
       9 - 19 . (canceled) 
   
   
       20 . A receiver for use in a wireless communications device, supporting both zero intermediate frequency (ZIF) and near-zero intermediate frequency (NZIF) operation, the receiver comprising:
 an RF front-end segment including a down-conversion segment;   a programmable synthesizer component operatively associated with a local oscillator segment;   the local oscillator segment operatively associated with the down-conversion segment;   an analog-to-digital conversion (ADC) segment adapted to receive signals from the down-conversion segment;   a digital intermediate frequency construct adapted to receive digital signals from the ADC segment; and   a digital to analog segment adapted to receive digital signals from the digital intermediate frequency construct.   
   
   
       21 . The receiver of  claim 20 , wherein the wireless communications device supports Wideband Code Division Multiple Access (WCDMA) operation mode. 
   
   
       22 . The receiver of  claim 20 , wherein the wireless communications device supports Global System for Mobile communications (GSM) operation mode. 
   
   
       23 . The receiver of  claim 20 , wherein the wireless communications device supports both Wideband Code Division Multiple Access (WCDMA) and Global System for Mobile communications (GSM) operation modes. 
   
   
       24 . The receiver of  claim 20 , wherein the down conversion segment comprises a demodulation element having the local oscillator segment operatively associated therewith. 
   
   
       25 . The receiver of  claim 20 , wherein the reconfigurable digital intermediate frequency construct comprises:
 an analog DC offset compensation element;   a digital mixer element;   a channel filtering element;   a digital DC offset compensation element; and   a variable gain amplification element.   
   
   
       26 . The receiver of  claim 25 , wherein the digital mixer element is driven by an oscillator element. 
   
   
       27 . The receiver of  claim 25 , wherein the digital mixer element is bypassed or disabled during ZIF operation. 
   
   
       28 . The receiver of  claim 25 , wherein the RF front-end segment further includes a low noise amplifier segment. 
   
   
       29 . A for processing a signal in a receiver for use in a wireless communications device, supporting both zero intermediate frequency (ZIF) and near-zero intermediate frequency (NZIF) operation, the method comprising:
 receiving a plurality of signals;   converting the received signals into a digital form;   processing the received signals along at least two paths;   performing mismatch compensation on the received signals;   performing coarse gain adjustment on the received signals;   amplifying the adjusted signals to a specified level; and   performing interpolation filtering of the amplified signals.   
   
   
       30 . The method of  claim 29 , further comprising:
 performing DC offset compensation on NZIF-based signals; and   performing at least one of droop compensation and cascaded integrator-comb filtering on the received signals.   
   
   
       31 . The method of  claim 29 , further comprising performing image rejection on NZIF-based signals.