INCREASING CAPACITY WITH SPATIAL-DIVISION MULTIPLE-ACESS IN WIRELESS COMMUNICATION NETWORKS

THE DEMAND FOR SERVICE IN THE MOBILE COMMUNICATIONS INDUSTRYCONTINUES TO RISE TO MEET THAT WHICH THE AVAILABLE RESOURCESCAN SUPPLY. SINCE FREQUENCY/BANDWIDTH IS DIMINISHING RESOURCE, OTHER RESOURCES WILL HAVE TO BE DEVELOPED, AND QUICKLY, IF THE INCREASING DEMAND FOR SERVICE IS TO BE MET. AS IT SO HAPPENS, THERE IS VIRGIN TERRITORY YET TO BE EXPLORED IN COMMUNICATION NETWORKS, "SPACE, THE FINAL FRONTIER", AND IT IS JUST WAITING TO BE TAPPED. BY OPENING UP A WHOLE NEW DIMENSION, SPACE, THAT CAN BE PACKED WITH SIGNALS, SINGLE-USER CHANNELS, FREQUENCY SLOTS IN A LOCALIZED CELL FOR EXAMPLE, CAN BE CONVERTED INTO MULTI-USERCHANNELS. THE GOAL IS TO ACCOMPLISH THIS WHILE STILL MAINTAINING THE QUALITY OF LINKS AS MEASURED BY OUTPUT SINR,OR BER, WHICHEVER IS APPROPRIATE. THE BASIC IDEA BEHIND THEPROPOSED RESEARCH IS TO ESTABLISH MULTIPLE SPATIAL CHANNELS AT THE SAME "FREQUENCY", I.E., SPATIAL-DIVISION MULTIPLE-ACCESS (SDMA). CLEARLY IF THIS CAN BE SUCCESSFULLYACCOMPLISHED, THE INCREASE IN CAPACITY IS SIGNIFICANT. THE OBJECTIVE OF THE PROPOSED EFFORT IS TO ASCERTAIN THE APPLICABILITY OF ESPRIT, A TECHNIQUE FOR REAL-TIME SIGNAL PARAMETER ESTIMATION, AND RELATED CONCEPTS TO THE WIRELESS INFORMATION NETWORK ENVIRONMENT INCLUDING BOTH MOBILE COMMUNICATIONS, DIGITAL OR ANALOG, AND PERSONAL COMMUNICATION NETWORKS. IN PHASE I, RESEARCH INTO AND DEVELOPMENT OF ACCURATE SOFTWARE MODELS OF THE ELECTROMAGNETIC ENVIRONMENT WILL BE CONDUCTED. THESE MODELSWILL BE USED TO SIMULATE REALISTIC SCENARIOS ON WHICH ESPRITAND RELATED ALGORITHMS CAN BE TESTED AND APPROPRIATE SIGNAL DETECTION, ESTIMATION AND DEMODULATION TECHNIQUES DEVELOPED. IT IS ANTICIPATED THAT PHASE I WILL CULMINATE INTHE SPECIFICATION OF AN EXPERIMENTAL SYSTEM FOR TESTING THE PROPOSED TECHNIQUES IN A REALISTIC ENVIRONMENT. THE COMMERCIALIZATION OF SUCH A SYSTEM WOULD HAVE A SIGNIFICANT IMPACT ON THE FUTURE OF WIRELESS COMMUNICATIONS, BOTH DOMESTIC AND FOREIGN, AND WOULD CONTRIBUTE SUBSTANTIALLY TO THE COMPETITIVENESS OF DOMESTIC COMMUNICATIONS RELATED INDUSTRIES IN THE WORLD MARKETPLACE.