Separation of AM cochannel signals in an overloaded signal environment

Abstract

Multiple cochannel AM signals received in an overloaded signal environment may be separated using RF data through a method of iterative projections.

1 . A method for processing AM signals, comprising: 
 receiving RF data in an overloaded signal environment, said received RF data comprising cochannel AM signals received in the same frequency range and at the same time; and    separating each of said cochannel AM signals from other cochannel AM signals of said received RF data.    
   
   
       2 . The method of  claim 1 , wherein said separating comprises estimating each of said cochannel AM signals based on said received RF data.  
   
   
       3 . The method of  claim 1 , wherein said cochannel AM signals are transmitted from geographically remote locations; and wherein said method further comprises receiving said RF data comprising said cochannel AM signals transmitted from geographically remote locations.  
   
   
       4 . The method of  claim 3 , wherein said separating comprises estimating each of said cochannel AM signals based on said received RF data.  
   
   
       5 . The method of  claim 1 , wherein said cochannel AM signals comprise a first cochannel AM signal transmitted from a first transmitter and a second cochannel AM signal simultaneously transmitted from a second transmitter, said first and second transmitters being positioned at geographically remote locations from each other; and wherein said method further comprises: 
 providing a receiver;    geographically positioning said receiver between said first transmitter and said second transmitter;    receiving said first cochannel AM signal transmitted by said first transmitter and said second cochannel AM signal simultaneously transmitted by said second transmitter at said receiver while said receiver is geographically positioned between said first transmitter and said second transmitter; and    separating said received first cochannel AM signal from said received second cochannel AM signal.    
   
   
       6 . The method of  claim 5 , wherein said first and second transmitters are located in separate cities.  
   
   
       7 . The method of  claim 1 , wherein said overloaded signal environment is created by intentionally broadcasting said cochannel AM signals simultaneously in the same frequency range.  
   
   
       8 . The method of  claim 7 , wherein one of said cochannel AM signals comprises public service information; and wherein said method further comprises isolating said AM signal comprising said public service information from other cochannel AM signals of said received RF data.  
   
   
       9 . The method of  claim 7 , wherein said method further comprises selectively isolating a given one of said cochannel AM signals from other cochannel AM signals of said received RF data in response to a command specifying the identity of said given one of said cochannel AM signals.  
   
   
       10 . A method for transmitting AM signals, comprising providing RF data comprising cochannel AM signals for transmission in the same frequency range and at the same time for reception by a receiver operating in an overloaded signal environment, said receiver configured to separate each of said cochannel AM signals from other cochannel AM signals of said RF data.  
   
   
       11 . The method of  claim 10 , further comprising transmitting said cochannel AM signals from geographically remote locations.  
   
   
       12 . The method of  claim 10 , wherein said cochannel AM signals comprise first and second cochannel AM signals; and wherein said method further comprises transmitting a first cochannel AM signal from a first transmitter and transmitting a second cochannel AM signal simultaneously from a second transmitter, said first and second transmitters being positioned at geographically remote locations from each other, and said receiver being geographically positioned between said first transmitter and said second transmitter for receiving said first cochannel AM signal transmitted by said first transmitter and said second cochannel AM signal simultaneously transmitted by said second transmitter.  
   
   
       13 . The method of  claim 12 , wherein said first and second transmitters are located in separate cities.  
   
   
       14 . The method of  claim 10 , wherein one of said cochannel AM signals comprises public service information; and wherein said receiver is further configured to isolate said AM signal comprising said public service information from other cochannel AM signals of said received RF data.  
   
   
       15 . The method of  claim 10 , wherein said receiver is further configured to selectively isolate a given one of said cochannel AM signals from other cochannel AM signals of said received RF data in response to a command specifying the identity of said given one of said cochannel AM signals.  
   
   
       16 . The method of  claim 14 , wherein said method further comprises receiving said transmitted RF data comprising cochannel AM signals; and separating each of said cochannel AM signals from other cochannel AM signals of said RF data.  
   
   
       17 . A system for communication using an overloaded signal environment, said system comprising: 
 transmit circuitry configured to provide RF data comprising cochannel AM signals for transmission in the same frequency range and at the same time; and    receive and separation circuitry configured to receive and separate each of said cochannel AM signals from other cochannel AM signals of said RF data.    
   
   
       18 . The system of  claim 17 , wherein said transmit circuitry is configured to provide said RF data for transmission of said cochannel AM signals in the same frequency range and at the same time from geographically remote locations.  
   
   
       19 . The system of  claim 17 , wherein said cochannel AM signals comprise first and second cochannel AM signals; and wherein said transmit circuitry comprises a first transmitter configured to transmit a first cochannel AM signal and a second transmitter configured to simultaneously transmit a second cochannel AM signal, said first and second transmitters being positioned at geographically remote locations from each other; and wherein said receive and separation circuitry is geographically positioned between said first transmitter and said second transmitter for receiving said first cochannel AM signal transmitted by said first transmitter and said second cochannel AM signal simultaneously transmitted by said second transmitter.  
   
   
       20 . The system of  claim 19 , wherein said first and second transmitters are located in separate cities.  
   
   
       21 . An AM signal processing system, comprising: 
 receive and separation circuitry coupled to receive RF data from at least one sensor operating in an overloaded signal environment, said received RF data comprising cochannel AM signals received in the same frequency range and at the same time; and    wherein said receive and separation circuitry is configured to separate each of said cochannel AM signals from other cochannel AM signals of said received RF data.    
   
   
       22 . The system of  claim 21 , wherein said receive and separation circuitry is configured to separate each of said cochannel AM signals from said other cochannel AM signals by estimating each of said cochannel AM signals based on said received RF data.  
   
   
       23 . The system of  claim 21 , wherein said receive and separation circuitry is coupled to receive RF data comprising cochannel AM signals transmitted from geographically remote locations; and wherein said receive and separation circuitry is configured to separate each of said cochannel AM signals from other cochannel AM signals that are transmitted from geographically remote locations.  
   
   
       24 . The system of  claim 23 , wherein said receive and separation circuitry is configured to separate each of said cochannel AM signals from said other cochannel AM signals by estimating each of said cochannel AM signals based on said received RF data.  
   
   
       25 . The system of  claim 21 , wherein said cochannel AM signals comprise a first cochannel AM signal transmitted from a first transmitter and a second cochannel AM signal simultaneously transmitted from a second transmitter, said first and second transmitters being positioned at geographically remote locations from each other; wherein said receive and separation circuitry is further configured to receive said first cochannel AM signal transmitted by said first transmitter and said second cochannel AM signal simultaneously transmitted by said second transmitter while said receiver is geographically positioned between said first transmitter and said second transmitter; wherein said receive and separation circuitry is further configured to separate said received first cochannel AM signal from said received second cochannel AM signal.  
   
   
       26 . The system of  claim 21 , wherein one of said cochannel AM signals comprises public service information; and wherein said receive and separation circuitry is further configured to isolate said AM signal comprising said public service information from other cochannel AM signals of said received RF data.  
   
   
       27 . The system of  claim 21 , wherein said receive and separation circuitry is further configured to selectively isolate a given one of said cochannel AM signals from other cochannel AM signals of said received RF data in response to a command specifying the identity of said given one of said cochannel AM signals.