Simple block space time transmit diversity using multiple spreading codes

Abstract

The present invention is a system and method for use in a CDMA communication system including a plurality of base stations and a user equipment (UE), each for communicating with each other. The base station has a transmitter which includes a first and second antenna for transmitting a data field of symbols. The first spreading device spreads the first data field using a first channelization code and the second spreading device spreads the second data field using a second channelization code, each channelization code being uniquely associated with one of the first and second antennas. The UE has a receiver for receiving a signal including the first and second spread data fields. The UE includes a joint detection device for detecting the symbols of the first and second data fields using the first and second channelization codes and a decoder for decoding the detected data fields to generate a single data field of symbols.

What is claimed is:  
     
         1 . A method for transmitting a data field of symbols in a CDMA communication system including a plurality of base stations and a user equipment (UE), wherein each of said base stations include a transmitter and said UE includes a receiver, the method comprising the steps of: 
 generating a first data field of symbols;    encoding said first data field producing a second data field having complex conjugates of the symbols of said data field;    spreading said first and second data fields, wherein said first data field is spread using a first channelization code and said second data field is spread using a second channelization code, each channelization code being uniquely associated with one of a first and second antennas;    transmitting an RF signal including said first and second spread data fields over a first and second antenna of said transmitter;    detecting the symbols of said first and second data fields using said first and second channelization codes; and    decoding said detected data fields to generate a single data field of symbols.    
     
     
         2 . The method of  claim 1  further comprising the step of scrambling said first and second spread data fields by a scrambling code associated with said transmitter.  
     
     
         3 . The method of  claim 2  wherein the symbols of said first data field of symbols are grouped into a first and second sub-data field.  
     
     
         4 . The method of  claim 3 , wherein the symbols of said second data field of symbols are grouped into a third and fourth sub-data field, wherein said third sub-data field is the negative complex conjugate of said second sub-data field and said fourth sub-data field is the complex conjugate of said first sub-data field.  
     
     
         5 . The method of  claim 4  wherein said base station further includes said receiver; and said UE further includes said transmitter.  
     
     
         6 . A transmitter for transmitting a data field of symbols in a CDMA communications system including a plurality of base stations and a user equipment (UE), said base stations including said transmitter and said UE including a receiver for communicating with each other, the transmitter comprising: 
 a first and second antenna for transmitting said data field of symbols;    an encoder for encoding said data field producing a second data field having complex conjugates of the symbols of said data field; and    a first and second spreading device for spreading said first and second data fields, wherein said first spreading device spreads said first data field using a first channelization code and said second spreading device spreads said second data field using a second channelization code, each channelization code being uniquely associated with one of said first and second antennas.    
     
     
         7 . The transmitter of  claim 6  further comprising a first and second scrambling device for scrambling said first and second spread data fields by a single scrambling code associated with said transmitter.  
     
     
         8 . The transmitter of  claim 7  wherein said receiver for receiving a signal including said first and second spread data field, comprises: 
 a joint detection device for detecting the symbols of said first and second data fields using said first and second channelization codes; and  
 a decoder for decoding said detected data fields to generate a single data field of symbols.  
 
     
     
         9 . The transmitter of  claim 8  wherein the symbols of said first data field of symbols are grouped into a first and second sub-data field.  
     
     
         10 . The transmitter of  claim 9 , wherein the symbols of said second data field of symbols are grouped into a third and fourth sub-data field, said third sub-data field being the negative complex conjugate of said second sub-data field and said fourth sub-data field being the complex conjugate of said first sub-data field.  
     
     
         11 . A CDMA communication system including a plurality of base stations and a user equipment (UE), each for communicating with each other, said plurality of base stations having a transmitter including: 
 a first and second means for transmitting a data field of symbols including a first data field;    a means for encoding said data field producing a second data field having complex conjugates of the symbols of said data field; and    a first and second spreading means for spreading said first and second data fields, wherein said first spreading means spreads said first data field using a first channelization code and said second spreading means spreads said second data field using a second channelization code, each channelization code being uniquely associated with one of said first and second transmitting means;    said UE having a means for receiving a signal including said first and second spread data fields, comprising: 
 a means for detecting the symbols of said first and second data fields using said first and second channelization codes; and  
 a means for decoding said detected data fields to generate a single data field of symbols.  
   
     
     
         12 . The system of  claim 11  further comprising a means for scrambling said first and second spread data fields by a scrambling code associated with said transmitting means.  
     
     
         13 . The system of  claim 12  wherein the symbols of said first data field of symbols are grouped into a first and second sub-data field.  
     
     
         14 . The system of  claim 13 , wherein the symbols of said second data field of symbols are grouped into a third and fourth sub-data field, wherein said third sub-data field is the negative complex conjugate of said second sub-data field and said fourth sub-data field is the complex conjugate of said first sub-data field.  
     
     
         15 . The system of  claim 14  wherein said base station further includes said means for receiving and said UE further includes said transmitting means.  
     
     
         16 . A method for transmitting a data field of symbols in a CDMA communication system including a plurality of base stations and a user equipment (UE), wherein each of said base stations include a transmitter and said UE includes a receiver, the method comprising the steps of: 
 generating a data field of symbols;    spreading said first data field using a first channelization code producing a first spread data field;    spreading said first data field using a second channelization code producing a second spread data field, each channelization code being uniquely associated with one of a first and second antennas;    transmitting an RF signal including said first and second spread data fields over a first and second antenna;    detecting the symbols of said data field using said first and second channelization codes; and    decoding said detected data field to generate a single data field of symbols.    
     
     
         17 . The method of  claim 16  further comprising the steps of scrambling said first and second spread data fields by a scrambling code associated with said transmitter.  
     
     
         18 . The method of  claim 17  wherein said base station further includes said receiver and said UE further includes said transmitter.  
     
     
         19 . A transmitter for transmitting a data field of symbols in a CDMA communications system including a plurality of base stations and a user equipment (UE), said base stations including said transmitter and said UE including a receiver for communicating with each other, the transmitter comprising: 
 a first and second antenna for transmitting said data field of symbols; and    a first and second spreading device for spreading said data field, wherein said first spreading device spreads said data field using a first channelization code, producing a first spread data field, and said second spreading device spreads said data field using a second channelization code, producing a second spread data field, each channelization code being uniquely associated with one of said first and second antennas.    
     
     
         20 . The transmitter of  claim 19  further comprising a first and second scrambling device for scrambling said first and second spread data fields by a single scrambling code associated with said transmitter.  
     
     
         21 . The transmitter of  claim 20  wherein said receiver for receiving a signal including said first and second spread data fields comprises: 
 a joint detection device for detecting the symbols of said data fields using said first and second channelization codes; and  
 a decoder for decoding said detected data fields to generate a single data field of symbols.  
 
     
     
         22 . A CDMA communication system including a plurality of base stations and a user equipment (UE), each for communicating with each other, said plurality of base stations having a transmitter including: 
 a first and second means for transmitting a data field of symbols;    a first and second spreading means for spreading said data field, wherein said first spreading means spreads said data field using a first channelization code producing a first spread data field and said second spreading means spreads said second data field using a second channelization code producing a second spread data field, each channelization code being uniquely associated with one of said first and second transmitting means;    said UE having a means for receiving a signal including said first and second spread data fields, comprising: 
 a means for detecting the symbols of said first and second spread data fields using said first and second channelization codes; and  
 a means for decoding said detected data fields to generate a single data field of symbols.  
   
     
     
         23 . The system of  claim 22  further comprising a means for scrambling said first and second spread data fields by a scrambling code associated with said transmitting means.