Harq buffer management and feedback design for a wireless system

Abstract

A method is disclosed for performing HARQ buffer management. The HARQ buffer management method is a new approach to buffer overflow management that allows the mobile station, rather than the base station, to control the size of its buffer. The HARQ buffer management reports buffer size, buffer occupancy status, and buffer overflow to the base station, to facilitate efficient communication between the base station and the mobile station.

1 . A method to manage a hybrid automatic repeat request (HARQ) buffer, the method comprising:
 transmitting a buffer size to a base station, the buffer size indicating the size of the HARQ buffer, wherein the buffer size is transmitted when the size of the HARQ buffer changes;   if the HARQ buffer overflows, transmitting a buffer overflow indicator to the base station; and   managing the size of the HARQ buffer without input from the base station.   
     
     
         2 . The method of  claim 1 , further comprising:
 if occupancy of the buffer exceeds a predetermined threshold, transmitting a buffer occupancy notification to the base station.   
     
     
         3 . The method of  claim 1 , transmitting a buffer size to a base station further comprising:
 transmitting the buffer size in a secondary fast feedback channel to the base station.   
     
     
         4 . The method of  claim 2 , transmitting a buffer occupancy notification to the base station further comprising:
 transmitting the buffer occupancy notification as a code word using a primary fast feedback channel to the base station.   
     
     
         5 . The method of  claim 2 , transmitting a buffer occupancy notification to the base station further comprising:
 transmitting the buffer occupancy notification as a bit using a bandwidth request channel.   
     
     
         6 . The method of  claim 2 , further comprising:
 transmitting the buffer occupancy notification and buffer overflow indicator as a code word using a primary fast feedback channel to the base station.   
     
     
         7 . The method of  claim 2 , further comprising:
 transmitting the buffer size, buffer occupancy notification, and buffer overflow indicator using an uplink feedback channel.   
     
     
         8 . The method of  claim 1 , managing the size of the HARQ buffer without input from the base station further comprising:
 evacuating correctly decoded forward error correction blocks from the HARQ buffer.   
     
     
         9 . The method of  claim 1 , managing the size of the HARQ buffer without input from the base station further comprising:
 evacuate soft parity bits from the HARQ buffer; and   store systematic bits in the HARQ buffer, wherein the systematic bits positively affect decoder performance.   
     
     
         10 . The method of  claim 1 , managing the size of the HARQ buffer without input from the base station further comprising:
 not storing mother coded bits in the HARQ buffer.   
     
     
         11 . The method of  claim 1 , managing the size of the HARQ buffer without input from the base station further comprising:
 storing some blocks received from the base station into the HARQ buffer in a compressed manner that enables HARQ combining gain while using fewer memory bits; and   not storing some other blocks received from the base station into the HARQ buffer;   
       wherein the stored blocks are sufficient to decode as a lossy version of data transmitted by the base station. 
     
     
         12 . A method to manage a hybrid automatic repeat request (HARQ) buffer, the method comprising:
 receiving a buffer size from a mobile station, the buffer size indicating the size of the HARQ buffer within the mobile station, wherein the buffer size is received when the size of the HARQ buffer changes;   if the HARQ buffer overflows, receiving a buffer overflow indicator from the mobile station; and   managing the traffic rate to the mobile station without managing the HARQ buffer.   
     
     
         13 . The method of  claim 12 , further comprising:
 if occupancy of the HARQ buffer exceeds a predetermined threshold, receiving a buffer occupancy notification from the mobile station.   
     
     
         14 . The method of  claim 12 , receiving a buffer size from a mobile station further comprising:
 receiving a buffer size from a secondary fast feedback channel, wherein the secondary fast feedback channel comprises up to twenty-four bits.   
     
     
         15 . The method of  claim 13 , further comprising:
 receiving the buffer overflow indicator and buffer occupancy notification as a code word in a primary fast feedback channel.   
     
     
         16 . The method of  claim 12 , further comprising:
 receiving the buffer overflow indicator as a bit in a bandwidth request channel.   
     
     
         17 . The method of  claim 13 , further comprising:
 receiving the buffer occupancy notification as a bit in a bandwidth request channel.   
     
     
         18 . A method, comprising:
 managing a hybrid automatic repeat request (HARQ) buffer for use in a wireless system, wherein the management comprises:
 sending a size of the HARQ buffer to a serving base station when the size of the HARQ buffer changes; 
 sending a buffer overflow indication to the base station if the buffer is full; and 
 sending a buffer occupancy indicator to the base station if the buffer contents exceed a predetermined threshold. 
   
     
     
         19 . The method of  claim 18 , managing a HARQ buffer further comprising:
 receiving blocks from the base station, the blocks comprising both decode bits and receive bits;   storing the decode bits in the HARQ buffer; and   not storing the receive bits in the HARQ buffer.   
     
     
         20 . The method of  claim 19 , not storing the receive bits in the HARQ buffer further comprising:
 not storing forward error correction bits in the HARQ buffer.