System and method using adaptive antennas to selectively reuse common physical channel timeslots for dedicated channels

Abstract

A method and communication system (e.g., a time-division duplex (TDD) system) that uses adaptive antennas at the base stations to monitor metrics associated with the quality of one or more common physical channel (CPCH) timeslots, so as to determine whether to reuse some or all of the CPCH timeslots to transmit a dedicated physical channel (DPCH). If it is determined to reuse some or all of the CPCH timeslots, an additional determination is made as to what limit to apply on the DPCH transmission powers. Adaptive antennas may be used at the base stations to allow the system to reuse some or all of the CPCH timeslots to transmit DPCH, thus improving the overall capacity of the system while maintaining the CPCH coverage and quality at a desired level throughout the system.

1 . In a wireless communication system including a plurality of cells, each cell having a plurality of angular sections, a method of reusing common physical channel (CPCH) timeslots to transmit dedicated physical channel (DPCH) signals, the method comprising: 
 (a) tagging at least one of the CPCH timeslots as being aggressive when the power of DPCH signals in the respective CPCH timeslot would cause interference if increased; and    (b) tagging at least one of the CPCH timeslots as being non-aggressive when the power of DPCH signals in the respective CPCH is increased if a predetermined DPCH signal maximum power level has not yet been reached.    
   
   
       2 . The method of  claim 1  further comprising: 
 (c) increasing by a predetermined amount the power of a DPCH signal transmitted for each CPCH timeslot that is tagged as being non-aggressive and the power is below a predetermined maximum power level;    (d) monitoring the metrics associated with the quality of the CPCH timeslot; and    (e) for each angular section of each cell associated with a degradation of CPCH quality, determining the respective neighboring cells, reducing the maximum power level for the CPCH timeslots in the neighboring cells associated with the degradation of CPCH quality, and tagging the neighboring cells as being aggressive for the CPCH timeslots associated with the degradation of CPCH quality.    
   
   
       3 . The method of  claim 2  further comprising: 
 (f) assigning a predetermined number of downlink timeslots; and    (g) assigning a predetermined number of CPCH timeslots, wherein the number of CPCH timeslots is between one and the number of downlink timeslots.    
   
   
       4 . The method of  claim 1  wherein the communication system is a time-division duplex (TDD) system and the cells are TDD cells.  
   
   
       5 . A wireless communication system which reserves common physical channel (CPCH) timeslots, the system comprising: 
 (a) a database in which at least one CPCH timeslot is tagged as being aggressive when the power of dedicated physical channel (DPCH) signals in the respective CPCH timeslot would cause interference if increased, and at least one CPCH timeslot is tagged as being non-aggressive when the power of DPCH signals in the respective CPCH is increased if a predetermined DPCH signal maximum power level has not yet been reached; and    (b) a processor in communication with the database.    
   
   
       6 . The system of  claim 5  further comprising: 
 (c) a plurality of cells, each cell having a plurality of angular sections; and    (d) a process running on the processor for monitoring the metrics associated with the quality of the CPCH timeslot, wherein for each angular section of each cell associated with a degradation of CPCH quality, the respective neighboring cells are determined, the maximum power level for the CPCH timeslots in the neighboring cells associated with the degradation of CPCH quality is reduced, and in the database, the CPCH timeslots in the neighboring cells associated with the degradation of CPCH quality are tagged as being aggressive.    
   
   
       7 . The system of  claim 5  wherein the CPCH timeslots are reserved to transmit broadcast channel (BCH) signals.  
   
   
       8 . The system of  claim 5  wherein the CPCH timeslots are reused to transmit dedicated physical channel (DPCH) signals at a power level that does not exceed a maximum power level  
   
   
       9 . A wireless communication system including a plurality of cells and a database, each cell having a plurality of angular sections, the system for reusing common physical channel (CPCH) timeslots to transmit dedicated physical channel (DPCH) signals, the system comprising: 
 (a) means for tagging in the database each CPCH timeslot as being aggressive or non-aggressive; and    (b) means for increasing by a predetermined amount the power of a DPCH signal transmitted for each CPCH timeslot that is tagged as being non-aggressive and the power is below a predetermined maximum power level.    
   
   
       10 . The system of  claim 9  further comprising: 
 (c) means for monitoring the metrics associated with the quality of the CPCH timeslot;    (d) means for determining the respective neighboring cells for each angular section of each cell associated with a degradation of CPCH quality;    (e) means for reducing the maximum power level for the CPCH timeslots in the neighboring cells associated with the degradation of CPCH quality; and    (f) means for tagging in the database the CPCH timeslots in the neighboring cells associated with the degradation of CPCH quality as being aggressive.    
   
   
       11 . The system of  claim 9  wherein the system is a time-division duplex (TDD) system and the cells are TDD cells.