Method and device for receiving information symbols over multiplexed channels

Abstract

A scheme for multiplexing transport channels on one or several communication channels is used to operate in a normal mode and in a compressed mode which requires a lower symbol rate to provide in active periods in the communication channels. To match the symbol rate on each of the transport channels, a symbol puncturing is performed in two passes: marked symbols are introduced and are subjected, along with the other information symbols, to different operations including an interleaving, before being deleted from the transmitted sequence. Accordingly, those operations can be performed in the same manner in the normal and compressed modes, which limits the complexity of the communicating entities.

1 . Method of processing Y digital streams obtained from a received signal and comprising estimates of information symbols respectively transmitted along Y communication channels simultaneously occupying a transmission resource organized as successive frames, and pertaining to X transport channels, X and Y being positive integers, wherein the successive frames include compressed-mode frames each having at least one inactive period during which no symbol is transmitted, and wherein the estimates of information symbols pertaining to each transport channel i (1≦i≦X) are received in successive transmission time intervals each comprising F i  consecutive frames, F i  being a positive integer,  
     the method comprising the following steps for each frame: 
 forming, in relation to each communication channel j (1≦j≦Y) a first sequence composed of estimates extracted from the time slots of said frame and, when said frame is in compressed mode, of marked estimates placed at positions corresponding to the inactive period of said frame;  
 for each communication channel, forming a second sequence of estimates by a permutation of the estimates of the first sequence;  
 forming a third sequence of estimates including estimates of the second sequence output for each communication channel; and  
 distributing the estimates of the third sequence into X segments of consecutive estimates, the X segments being respectively assigned to the X transport channels,  
 and the following steps for each transmission time interval relating to a transport channel:  
 forming a fourth sequence by concatenating the respective segments assigned to said transport channel for the frames of said transmission time interval;  
 permuting the estimates of the fourth sequence and forming a fifth sequence of estimates extracted from the permuted fourth sequence;  
 ignoring each marked estimate of the fifth sequence, and forming a sixth sequence of symbols on the basis of the other estimates of the fifth sequence; and  
 decoding the sixth sequence of estimates and outputting the decoded estimates.  
 
   
   
       2 . Method according to  claim 1 , wherein the step of forming the third sequence for at least one frame comprises concatenating the second sequences formed for the Y communication channels and deleting at least one estimate having a determined position in the concatenated sequence.  
   
   
       3 . Method according to  claim 1 , wherein the step of forming the fifth sequence for at least one transmission time interval relating to a transport channel comprises deleting at least one estimate having a determined position in the permuted fourth sequence.  
   
   
       4 . Device for processing Y digital streams obtained from a received signal and comprising estimates of information symbols respectively transmitted along Y communication channels simultaneously occupying a transmission resource organized as successive frames, and pertaining to X transport channels, X and Y being positive integers, the successive frames including compressed-mode frames each having at least one inactive period during which no symbol is transmitted, and the estimates of information symbols pertaining to each transport channel i (1≦i≦X) being received in successive transmission time intervals each comprising F i  consecutive frames, F i  being a positive integer, the device comprising: 
 means for forming, for each frame in relation to each communication channel, a first sequence composed of estimates extracted from the time slots of said frame and, when said frame is in compressed mode, marked estimates placed at positions corresponding to the inactive period of said frame;    means for forming, for each frame in relation to each communication channel, a second sequence of estimates by permutation of the estimates of the first sequence;    means for forming, for each frame, a third sequence of estimates including estimates of the second sequence output for each communication channel;    means for distributing the estimates of the third sequence formed for each frame into X segments of consecutive estimates, the X segments being respectively assigned to the X transport channels;    means for forming a fourth sequence for each transmission time interval relating to a transport channel, by concatenating the respective segments assigned to said transport channel for the frames of said transmission time interval;    means for permuting the estimates of the fourth sequence formed for each transmission time interval relating to transport channel, and for forming a fifth sequence of estimates extracted from the fourth permuted sequence;    means for deleting each marked estimate of the fifth sequence formed for each transmission time interval relating to a transport channel, and for forming a sixth sequence of symbols on the basis of the other estimates of the fifth sequence; and    means for decoding the sixth sequence of estimates formed for each transmission time interval relating to a transport channel, to output the decoded estimates.    
   
   
       5 . Device according to  claim 4 , wherein the means for forming the third sequence of estimates comprise means for concatenating the second sequences formed for the Y communication channels and means for deleting at least one estimate having a determined position in the concatenated sequence.  
   
   
       6 . Device according to  claim 4 , wherein the means for forming the fifth sequence comprise means for deleting at least one estimate having a determined position in the permuted fourth sequence.  
   
   
       7 . Radiocommunication terminal, comprising reception means to provide Y digital streams from a received signal and processing means for processing said Y digital streams to feed X transport channels, X and Y being positive integers, said Y digital streams including estimates of information symbols pertaining to the X transport channels and respectively transmitted along Y communication channels simultaneously occupying a transmission resource organized as successive frames, the successive frames including compressed-mode frames each having at least one inactive period during which no symbol is transmitted, the estimates of information symbols pertaining to each transport channel i (1≦i≦X) being received in successive transmission time intervals each comprising F i  consecutive frames, F i  being a positive integer, wherein the processing means comprise: 
 means for forming, for each frame in relation to each communication channel, a first sequence composed of estimates extracted from the time slots of said frame and, when said frame is in compressed mode, marked estimates placed at positions corresponding to the inactive period of said frame;    means for forming, for each frame in relation to each communication channel, a second sequence of estimates by permutation of the estimates of the first sequence;    means for forming, for each frame, a third sequence of estimates including estimates of the second sequence output for each communication channel;    means for distributing the estimates of the third sequence formed for each frame into X segments of consecutive estimates, the X segments being respectively assigned to the X transport channels;    means for forming a fourth sequence for each transmission time interval relating to a transport channel, by concatenating the respective segments assigned to said transport channel for the frames of said transmission time interval;    means for permuting the estimates of the fourth sequence formed for each transmission time interval relating to a transport channel, and for forming a fifth sequence of estimates extracted from the fourth permuted sequence;    means for deleting each marked estimate of the fifth sequence formed for each transmission time interval relating to a transport channel, and for forming a sixth sequence of symbols on the basis of the other estimates of the fifth sequence; and    means for decoding the sixth sequence of estimates formed for each transmission time interval relating to a transport channel, to output decoded estimates for the transport channel.    
   
   
       8 . Terminal according to  claim 7 , wherein the means for forming the third sequence of estimates comprise means for concatenating the second sequences formed for the Y communication channels and means for deleting at least one estimate having a determined position in the concatenated sequence.  
   
   
       9 . Terminal according to  claim 7 , wherein the means for forming the fifth sequence comprise means for deleting at least one estimate having a determined position in the permuted fourth sequence.