Polyphase channelization system

Abstract

A polyphase channelizer converts an intermediate frequency wideband signal into a complex signal that is sampled by parallel analog-to-digital converters having a bank of samplers respectively clocked by staggered clocking signals for respective converters for feeding I and Q quadrature samples to a polyphase filter bank of finite impulse response filters driving a fast Fourier transform processor for providing channelized digital signal outputs. The parallel analog-to-digital converters can operate at lower speeds but are parallel connected for effectively operating at required higher speeds. The channelizer channelizes the wideband signal using a polyphase clock for enabling high speed sampling and converting through low speed parallel analog to digital converters.

1. A system for channelizing an IF  a wideband input signal into separated channelized digital output signals, the system comprising,
 a complex mixer for quadrature demodulation of the IF  wideband input signal into a complex signal,  
 a polyphase clock generator for generating polyphase clock signals each having the same clocking signal that is staggered in phase over a clock cycle,  
 a parallel converter comprising a bank of samplers for respective sampling the complex signal into staggered sampled complex signals and comprising a bank of converters for converting the staggered sampled complex signals into respective sampled digital complex signals, each of the samplers of the bank of sampler sampling the complex signals at a rate of the clock cycle at a respective staggered phase, and  
 a parallel filter bank comprising a polyphase filter bank of filters for respective filtering the sampled digital complex signals into respective filtered complex signals and comprising a processor for transforming the filtered complex signals into the channelized digital output signals, the channelized digital output signals being separated from each other and corresponding to a respective plurality of frequency band signals of the IF  wideband input signal.  
 
     
     
       2. A system for channelizing an IF  a wideband input signal into separated channelized digital output signals, the system comprising,
 a complex mixer for quadrature demodulation of the IF  wideband input signal into a complex signal,  
 a polyphase clock generator for generating polyphase clock signals each having the same clocking signal that is staggered in phase over a clock cycle,  
 a parallel converter comprising a bank of samplers for respective sampling the complex signal into staggered sampled complex signals and comprising a bank of converters for converting the staggered sampled complex signals into respective sampled digital complex signals, each of the samplers of the bank of sampler sampling the complex signals at a rate of the clock cycle at a respective staggered phase, and  
 a parallel filter bank comprising a polyphase filter bank of filters for respective filtering the sampled digital complex signals into respective filtered complex signals and comprising a processor for transforming the filtered complex signals into the channelized digital output signals, wherein,  
 the processor is a Fast Fourier Transform processor for computing N point Fast Fourier transforms of the N filter complex signals once every clock cycle of (f s /N) −1  seconds.  
 
     
     
       3. The system of  claim 2  wherein,
 the polyphase filter bank comprises a plurality of digital filters each of which is a finite impulse response filter.  
 
     
     
       4. The system of  claim 2  wherein,
 the polyphase filter bank comprises a plurality of digital filters each of which is an infinite impulse response filter.  
 
     
     
       5. The system of  claim 2  wherein,
 the input signal comprises a plurality of channel signals that are frequency division multiple access signals having a channel bandwidth, and  
 the polyphase filter bank comprises a plurality of digital filters each of which having a bandwidth equal to ½ of a bandwidth of a respective channel signal in the input signal.  
 
     
     
       6. The system of  claim 2  wherein,
 the input signal is an IF wideband signal communicating channel signals communicated within a channel bandwidth,  
 the complex signal comprises I and Q quadrature baseband signals,  
 the staggered sampled complex signals are staggered sampled I and Q quadrature baseband signals, the sampled digital complex signals are digitized staggered sampled I and Q quadrature baseband signals,  
 the filtered complex signals are baseband channel signals within ½ of the channel bandwidth, and  
 the channelized digital output signals are separated baseband channel signals.  
 
     
     
       7. A system for channelizing an IF  a wideband signal into channelized digital output signals, the system comprising,
 a complex mixer for quadrature demodulation of the IF  wideband signal into a complex signal communicating channel signals communicated within a channel bandwidth, the complex signal comprises I and Q quadrature baseband signals,  
 a polyphase clock generator for generating polyphase clock signals each of which having the same clocking signal that is staggered in phase over a clock cycle,  
 a bank of samplers for respective sampling the I and Q baseband quadrature signals into staggered sampled I and Q quadrature signals, each of the samplers of the bank of sampler sampling the I and Q quadrature signals at a rate of the clock cycle at a respective staggered phase,  
 a bank of converters for converting the staggered sampled I and Q quadrature signals into respective sampled digital I and Q quadrature signals,  
 a polyphase filter bank of filters for respective filtering the sampled digital I and Q quadrature signals into respective filtered I and Q quadrature signals, and  
 a processor for transforming the filtered I and Q quadrature signals into the channelized digital output signals, the channelized digital output signals being separated from each other and corresponding to a respective plurality of frequency band signals of the IF  wideband signal.  
 
     
     
       8. The system of  claim 7  wherein,
 the processor is a Fast Fourier Transform processor for computing N point Fast Fourier transforms of the N filter complex signals once every clock cycle of (f s /N) −1  seconds, and  
 the polyphase filter bank comprises a plurality of digital filters each of which is a finite impulse response filter.  
 
     
     
       9. The system of  claim 7  wherein, the IF  wideband signal comprises a plurality of channel signals that are in frequency division multiple access signals having a channel bandwidth, and
 the polyphase filter bank comprises a plurality of digital filters each of which having a bandwidth equal to ½ of a bandwidth of a respective channel signal in the input signal.  
 
     
     
       10. A method for channelizing an IF wideband input signal into separated channelized digital output signals, the method comprising:
   quadrature demodulation of the IF wideband input signal into a complex signal;        generating polyphase clock signals;        sampling the complex signal with the polyphase clock signals in order to provide staggered sampled complex signals;        converting the staggered sampled complex signals into respective sampled digital complex signals at a rate of the polyphase clock signals;        filtering the respective sampled digital complex signals into respective filtered complex signals;        transforming the filtered complex signals into the channelized digital output signals, wherein the channelized digital output signals are separated from each other and correspond to a plurality of frequency band signals of the IF wideband signal,        wherein each of the polyphase clock signals has a clocking signal period  ( T   L )  that is in accordance with a first sample rate for a bandwidth of the channelized digital output signals, and        wherein each of the polyphase clock signals is staggered in phase relative to other adjacent polyphase clock signals by a second period  ( T   H )  that is in accordance with a sample rate for the IF wideband input.     
     
     
       11. A method for channelizing an IF wideband input signal into separated channelized digital output signals, the method comprising:
   quadrature demodulating of the IF wideband input signal into a complex signal,        generating polyphase clock signals each having a same clocking signal period and each having a staggered phase relative to adjacent polyphase clock signals,        sampling the complex signal into staggered sampled complex signals;        converting the staggered sampled complex signals into respective sampled digital complex signals;        filtering the sampled digital complex signals into respective filtered complex signals;        transforming the filtered complex signals into the channelized digital output signals,        wherein, the transforming is performed with a Fast Fourier Transform processor for computing N point Fast Fourier transforms of the N filter complex signals once every clocking signal period,        wherein each of the polyphase clock signals has the clocking signal period  ( T   L )  that is in accordance with a first sample rate for a bandwidth of the channelized digital output signals, and        wherein each of the polyphase clock signals is staggered in phase relative to adjacent polyphase clock signals by a second period  ( T   H )  that is in accordance with a sample rate for the IF wideband input.     
     
     
       12. The method of  claim 11 , wherein the filtering is performed by a plurality of digital filters each of which is a finite impulse response filter. 
     
     
       13. The method of  claim 11 , wherein the filtering is performed by a plurality of digital filters each of which is an infinite impulse response filter. 
     
     
       14. The method of  claim 12 , wherein the IF wideband input signal further comprises a plurality of channel signals that are frequency division multiple access signals having a channel bandwidth, and the plurality of digital filters each of which having a bandwidth equal to  1 / 2  of a bandwidth of a respective channel signal in the IF wideband input signal. 
     
     
       15. The method of  claim 13 , wherein the IF wideband input signal further comprises a plurality of channel signals that are frequency division multiple access signals having a channel bandwidth, and the plurality of digital filters each of which having a bandwidth equal to  1 / 2  of a bandwidth of a respective channel signal in the IF wideband input signal. 
     
     
       16. The method of  claim 11 , wherein the IF wideband input signal further comprises channel signals within a channel bandwidth, the complex signal further comprises I and Q quadrature baseband signals, the staggered sampled complex signals are staggered sampled I and Q quadrature baseband signals, the sampled digital complex signals are digitized staggered sampled I and Q quadrature baseband signals, the filtered complex signals are baseband channel signals within  1 / 2  of the channel bandwidth, and the channelized digital output signals are separated baseband channel signals. 
     
     
       17. A method for channelizing an IF wideband signal into channelized digital output signals, the method comprising:
   quadrature demodulating the IF wideband signal into a complex signal communicating channel signals communicated within a channel bandwidth, wherein the complex signal further comprises I and Q quadrature baseband signals;        generating polyphase clock signals each of which having the same clocking signal that is staggered in phase over a clock cycle;        sampling the I and Q baseband quadrature signals into staggered sampled I and Q quadrature signals, wherein the sampling of the I and Q quadrature signals is at a rate of the clock cycle at a respective staggered phase;        converting the staggered sampled I and Q quadrature signals into respective sampled digital I and Q quadrature signals;        filtering the sampled digital I and Q quadrature signals into respective filtered I and Q quadrature signals, and a processor for transforming the filtered I and Q quadrature signals into the channelized digital output signals;        wherein the channelized digital output signals are separated from each other and correspond to a respective plurality of frequency band signals of the IF wideband signal.     
     
     
       18. The method of  claim 17 , wherein the filtering is performed by a plurality of digital filters each of which is a finite impulse response filter, and
   wherein, the transforming is performed with a Fast Fourier Transform processor for computing N point Fast Fourier transforms of the N filter complex signals once every clocking signal period.     
     
     
       19. The method of  claim 17 , wherein the IF wideband input signal further comprises a plurality of channel signals that are in frequency division multiple access signals having a channel bandwidth, and wherein the filtering is performed by a plurality of digital filters, each of which has a bandwidth equal to  1 / 2  of a bandwidth of a respective channel signal in the IF wideband input signal.