Methods and systems for using a beam-forming network in conjunction with maximal-ratio-combining techniques

Abstract

Various methods and systems for (i) combining the capabilities of beam-forming networks together with the benefit of using maximal-ratio-combining techniques, and (ii) selecting receiving directions for wireless data packets in conjunction with beam-forming networks.

What is claimed is: 
     
         1 . A wireless communication system for generating a plurality of beams via an antenna array using combined capabilities of at least two beam-forming networks, said system comprising:
 an antenna array comprising two or more antennas, at least one of said two or more antennas being a cross-polarized antenna comprising a first-polarity input and a second-polarity input; and   a first beam-forming network and a second beam-forming network, each of said beam-forming networks comprising two or more array ports, each of said array ports being connected to one of said antennas;   wherein at least one of said array ports of said first beam-forming network is connected to said at least one cross-polarized antenna via said first-polarity input, and at least one of said array ports of said second beam-forming network is connected to said at least one cross-polarized antenna via said second-polarity input.   
     
     
         2 . The system of  claim 1 , wherein:
 all of said two or more antennas are cross-polarized antennas, each of said cross-polarized antennas comprising a first-polarity input and a second-polarity input;   said array ports of said first beam-forming network are connected to said two or more cross-polarized antennas, via said first-polarity input of each of said two or more cross-polarized antennas; and   said array ports of said second beam-forming network are connected to said two or more cross-polarized antennas, via said second-polarity input of each of said two or more cross-polarized antennas;   such that each of said two or more antennas is connected to both said first and said second beam-forming networks.   
     
     
         3 . The system of  claim 2 , wherein:
 said first beam-forming network comprises a first beam port and a second beam-port;   said second beam-forming network comprises a third beam-port and a fourth beam-port; and   said system is configured to:
 (1) generate first and second first-polarity-beams, the first first-polarity-beam having a first direction and the second first-polarity-beam having a second direction, by injecting a first radio-frequency signal into said first beam-port and a second radio-frequency signal into said second beam-port; and 
 (2) generate first and second second-polarity-beams, the first second-polarity-beam having a third direction and the second second-polarity-beam having a fourth direction, by injecting a third radio-frequency signal into said third beam-port and a fourth radio-frequency signal into said fourth beam-port. 
   
     
     
         4 . The system of  claim 3 , wherein said first and second beam-forming networks are selected from a group consisting of: (i) a rotman-lens, (ii) a butler-matrix, (iii) a blass-matrix, and (iv) a fixed or passive beam-forming network. 
     
     
         5 . The system of  claim 3 , wherein the first and second directions are different from said third and fourth directions. 
     
     
         6 . The system of  claim 5 , wherein said first and second beam-forming networks are butler-matrixes. 
     
     
         7 . The system of  claim 6 , wherein said first and second directions are made different than said third and fourth directions, by intentionally introducing radio-frequency phase shifts between said first and second array ports and said two or more antennas. 
     
     
         8 . The system of  claim 7 , wherein said radio-frequency phase shifts are progressively linear with array port number. 
     
     
         9 . The system of  claim 8 , wherein said radio-frequency phase shifts are static. 
     
     
         10 . The system of  claim 3 , wherein the radio-frequency signals at least partially conform to an IEEE-802.11 communication standard. 
     
     
         11 . The system of  claim 3 , wherein the radio-frequency signals at least partially conform to an IEEE-802.11n communication standard. 
     
     
         12 . The system of  claim 3 , wherein the radio-frequency signals at least partially conform to an IEEE-802.11ac communication standard. 
     
     
         13 . The system of  claim 3 , wherein the radio-frequency signals are within a frequency range of between 2.4 Ghz and 2.5 Ghz, and said first and second beam-forming networks are configured to operate directly in the frequency range. 
     
     
         14 . The system of  claim 3 , wherein the radio-frequency signals are within a frequency range of between 4.8 Ghz and 5.8 Ghz, and said first and second beam-forming networks are configured to operate directly in the frequency range. 
     
     
         15 . The system of  claim 2 , wherein said system is configured to:
 generate first and second first-polarity-beams, the first first-polarity-beam having a first direction and the second first-polarity-beam having a second direction, by applying appropriate radio-frequency signals by said first beam-forming network via said first-polarity input of each of said antennas; and   generate first and second second-polarity-beams, the first second-polarity-beam having a third direction and the second second-polarity-beam having a fourth direction, by applying appropriate radio-frequency signals by said second beam-forming network via said second-polarity input of each of said antennas.   
     
     
         16 . The system of  claim 15 , wherein said first and second beam-forming networks are selected from a group consisting of: (i) a digital-signal-processing based beam-forming network, (ii) an active-antenna-switching based beam-forming network, and (iii) a maximal-ratio-combining network. 
     
     
         17 . A method for increasing beam count by combining two beam-forming networks, said method comprising:
 generating a first set of beams having a first beam polarity using a first beam-forming network connected to a cross-polarized phased-array antenna via a set of first-polarity inputs; and   generating a second set of beams having a second beam polarity using a second beam-forming network connected to the cross-polarized phased-array antenna via a set of second-polarity inputs.   
     
     
         18 . The method of  claim 17 , wherein the first and second beam-forming networks are selected from a group consisting of: (i) a rotman-lens, (ii) a butler-matrix, (iii) a blass-matrix, and (iv) a fixed or passive beam-forming network. 
     
     
         19 . The method of  claim 17 , wherein said first and second beam-forming networks are butler-matrixes. 
     
     
         20 . The method of  claim 19 , wherein:
 N is a whole number larger than 2;   the cross-polarized phased-array antenna comprises N cross-polarized antennas each comprising a first polarity input and a second polarity input, such that the set of first-polarity inputs comprises N inputs and the set of second-polarity inputs comprises N inputs;   the first beam-forming network is of order N, comprising N array ports connected to the first-polarity inputs;   said second beam-forming network is of order N, comprising N array ports connected to the second-polarity inputs;   the first set of beams comprises N beams directed into N different directions; and   the second set of beams comprises N beams directed into N different directions;   generating a total of 2 times N beams.   
     
     
         21 . The method of  claim 20 , further comprising:
 introducing radio-frequency phase shifts between the N array ports of the first beam-forming network and the N cross-polarized antennas, the phase shifts being progressively linear with array port number, thereby generating the 2 times N beams in unique 2 times N directions.