Transmitter and transmitting method increasing the flexibility of code assignment

Abstract

According to the present invention aA transmitter and a transmitting method for communicating data symbols over a communication channel, for example, according to the CDMA system is presented . The transmitter ( 24, 25 ) comprises means ( 9 ) for spreadingA spreading section spreads each data symbol with a respective spreading code, wherein the. The spreading codes are mutually orthogonal. Means ( 10 ) for scrambling areA scrambling section is provided to scramble each spread symbol with a respective scrambling code, the scrambling codes respectively having the same length as the spreading codes . Furthermore, means ( 11 ) fora transmission section for the transmission of the spread and scrambled symbols are providedis provided. According to the present invention the means ( 10 ) for scrambling arethe scrambling section is provided with a plurality of different scrambling codes, which can be used simultaneously within the same link.

1. Transmitter for communicating data symbols over a communication channel, the transmitter comprising:
 means for spreading each data symbol with a respective spreading code,  
 wherein the spreading codes are mutually orthogonal,  
 means for scrambling each spread symbol with a respective scrambling code, the scrambling codes respectively having the same length as the spreading codes, and  
 means for transmitting said spread and scrambled symbols,  
 wherein the means for scrambling are provided with a plurality of different scrambling codes which can be used simultaneously within the same link so that a maximum data rate is increased.  
 
     
     
       2. Transmitter according to  claim 1 ,
 characterized in thatwherein the means for scrambling can use different scrambling codes for an uplink communication channel and a downlink communication channel, respectively.  
 
     
     
       3. Transmitter according  claim 1 ,
 characterized in thatwherein the spreading codes are obtained by means of a code tree.  
 
     
     
       4. Transmitter according to  claim 1 ,
 characterized in thatwherein only in a downlink communication channel different scrambling codes are used,  
 wherein in an uplink channel only one scrambling code is used.  
 
     
     
       5. Transmitter according to  claim 1 ,
 characterized in thatwherein the means for scrambling use different scrambling codes within the same link only for channels demanding a high bit rate.  
 
     
     
       6. Transmitter according to  claim 5 ,
 characterized in thatwherein the means for scrambling use different scrambling codes within the same link only video channels.  
 
     
     
       7. Wireless transmission system, comprising:
 means for spreading each data symbol with a respective spreading code,  
 wherein the spreading codes are mutually orthogonal,  
 means for scrambling each spread symbol with a respective scrambling code, the scrambling codes respectively having the same length as the spreading codes, and  
 means for transmitting said spread and scrambled symbols,  
 wherein the means for scrambling are provided with a plurality of different scrambling codes which can be used simultaneously within the same link so that a maximum data rate is increased, and  
 wherein a subset of scrambling codes is respectively allocated to a cell of the transmission system.  
 
     
     
       8. Wireless transmission system according to  claim 7 ,
 characterized in thatwherein different spreading codes are allocated to adjacent cells of the transmission system.  
 
     
     
       9. Method for the transmission of data symbols over a communication channel, comprising the following steps:
 spreading each data symbol with a respective spreading code,  
 wherein the spreading codes are mutually orthogonal,  
 scrambling each spread symbol with a respective scrambling code, the scrambling codes respectively having the same length as the spreading codes, and  
 transmitting said spread and scrambled symbols,  
 wherein the scrambling step provides a plurality of different scrambling codes which can be used simultaneously within the same link so that a maximum data rate is increased.  
 
     
     
       10. Method according to  claim 9 ,
 characterized in thatwherein in the step of scrambling different scrambling codes can be used for an uplink communication channel and a downlink communication channel, respectively.  
 
     
     
       11. Method according to  claim 9 ,
 characterized in thatwherein the spreading codes are obtained by means of a code tree.  
 
     
     
       12. Method according to  claim 9 ,
 characterized in thatwherein only in a downlink communication channel different scrambling codes are used,  
 wherein in an uplink channel only one scrambling code is used.  
 
     
     
       13. Method according to  claim 9 ,
 characterized in thatwherein different scrambling codes within the same link are used only for channels demanding a high bit rate.  
 
     
     
       14. Method according to  claim 13 ,
 characterized in thatwherein different scrambling codes within the same link are used only for video channels.  
 
     
     
       15. A method for the transmission of data symbols over a communication channel, comprising the following steps:
   spreading each data symbol with a respective spreading code,        wherein the spreading codes are mutually orthogonal,        scrambling each spread symbol with a respective scrambling code, and        transmitting the spread and scrambled symbols,        wherein for the step of scrambling a plurality of different scrambling codes is provided so that a maximum data rate is increased.     
     
     
       16. The method according to  claim 15 ,
   wherein transmitting is over a downlink and  512  different scrambling codes are provided.     
     
     
       17. The method according to  claim 16 ,
   wherein the scrambling codes are divided in groups.     
     
     
       18. The method according to  claim 17 ,
   wherein each scrambling code group is allocated to a cell of a transmission.     
     
     
       19. The method according to  claim 16 ,
   wherein different user terminals in the same cell use different scrambling codes.     
     
     
       20. A wireless transmission system, comprising a plurality of user terminals in one cell and respectively connected with an uplink transmission to the same base station,
   wherein each of the user terminals comprises:      means for spreading data symbols to be transmitted with a respective spreading code,        wherein the spreading codes are mutually orthogonal, and        means for scrambling each spread symbol with a respective scrambling code, and          wherein different user terminals in the same cell use different scrambling codes so that a maximum data rate is increased.     
     
     
       21. A transmitter for communicating data symbols over a communication channel comprising a plurality of sub- channels, the transmitter comprising:      means for spreading the data symbols of each sub - channel with a respective spreading code,        wherein the spreading codes are mutually orthogonal,        means for scrambling the spread symbols of each sub - channel with a scrambling code, and        means for the transmission of the spread and scrambled symbols of each sub - channel,        wherein said means for scrambling are designed to scramble different sub - channels with different scrambling codes so that a maximum data rate is increased.     
     
     
       22. Method for the transmission of data symbols over a communication channel comprising a plurality of sub- channels, comprising the following steps:      spreading the data symbols of each sub - channel with a respective spreading code,        wherein the spreading codes are mutually orthogonal,        scrambling the spread symbols of each sub - channel with a respective scrambling code,        wherein said sub - channels are scrambled with different scrambling codes so that a maximum data rate is increased, and        transmitting the spread and scrambled symbols of each sub - channel.