Seamless change of depth of a general convolutional interleaver during transmission without loss of data

Abstract

Methods and communication systems are presented, in which an interleaver depth is adjusted.

1 . A device comprising:
 a convolution interleaver configured to interleave the plurality of codewords or data blocks based on an interleaver depth, wherein the convolutional interleaver is capable to change the interleaver depth by an amount other than an integer multiple of the block length of the plurality of codewords or data blocks.   
     
     
         2 . The device according to  claim 1 , wherein the convolution interleaver is configured to insert dummy bytes in an output sequence of the convolution interleaver. 
     
     
         3 . The device according to  claim 2 , wherein the convolution interleaver is configured to increase the interleaver depth from a first interleaver depth D 1  to a second interleaver depth D 2 , wherein a number of dummy bytes inserted in the output sequence is determined by the sum obtained by summing up ΔT(z,y) for z=0 to I−1,
 wherein
   Δ T ( z,y )=floor[( D   2 −1)* z/I−T off 2 ( y )]−floor[( D   1 −1)* z/I−T off 1 ( y )] wherein
 
     T off j ( y )=[( D   j −1)* y/I −floor(( D   j −1)* y/I )],
 
 
 wherein D j  represents the interleaver depth either before the change in interleaver depth, wherein D j  is D 1 , or after the change in interleaver depth, wherein D j  is D 2 , and wherein floor(m) is a mathematical operator wherein the value “m” is rounded down to the next lowest integer value, and I comprises the number of bytes associated with a data block or codeword to be transmitted. 
 
     
     
         4 . The device according to  claim 2 , wherein the convolution interleaver is configured to increase the interleaver depth from D 1  to D 2 , wherein the convolution interleaver is further configured to change the interleaver depth such that a byte at the first position of the codeword or data block is read after the change, wherein the number of dummy bytes inserted in the output sequence is determined by the sum obtained by summing up the value ΔT(z) for all z=0 to I−1, wherein ΔT(z)=floor[(D 2 −1)*z/I]−floor[(D 1 −1)*z/I], and wherein floor(m) is a mathematical operator wherein the value “m” is rounded down to the next lowest integer value, and wherein I comprises the number of bytes associated with a data block or codeword. 
     
     
         5 . The device according to  claim 1 , wherein the convolution interleaver is configured to decrease the interleaver depth from a first depth D 1  to a second depth D 2  and to insert dummy bytes with a first byte pattern of dummy bytes, wherein the first byte pattern of dummy bytes corresponds to an inverted second byte pattern of dummy bytes, wherein the second byte pattern of dummy bytes is a byte pattern of dummy bytes the convolution interleaver would insert during an increase of the interleaver depth from D 2  to D 1 . 
     
     
         6 . The device according to  claim 1 , wherein the convolution interleaver is configured to provide convolution interleaving prior to the change of the interleaver depth according to a first data order and wherein the convolution interleaver is configured to provide convolution interleaving after the change of the interleaver depth according to a second data order, the second data order being different than the first data order. 
     
     
         7 . The device according to  claim 1 , wherein the device is a digital subscriber line transmitter device. 
     
     
         8 . The device according to  claim 1 , wherein the convolution interleaver is implemented on a semiconductor chip. 
     
     
         9 . A data transmission system comprising:
 a transmitter;   a first convolution interleaver, the first convolution interleaver configured to interleave the plurality of codewords or data blocks based on an interleaver depth, wherein the first convolution interleaver is capable to change the interleaver depth by an amount other than an integer multiple of the block length of the plurality of codewords or data blocks; and   a receiver; and   second convolution interleaver, the second convolution interleaver configured to interleave the plurality of codewords or data blocks based on an interleaver depth, wherein the second convolution interleaver is capable to change the interleaver depth by an amount other than an integer multiple of the block length of the plurality of codewords or data blocks.   
     
     
         10 . The data transmission system of  claim 9 , wherein the data transmission system is implemented as a digital subscriber line transmission system. 
     
     
         11 . A device comprising:
 convolutional interleaver configured to interleave a plurality of codewords or data blocks based on an interleaver depth;   wherein convolutional interleaver is configured to decrease the interleaver depth such that the plurality of codewords or data blocks are prior to the decrease of the interleaver depth convolution interleaved with a first interleaver depth D 1  and are after the decrease of the interleaver depth convolution interleaved with a second interleaver depth D 2 , wherein D 2 <D 1 ;   and wherein the convolutional interleaver is configured to selectively insert dummy bytes with a first pattern into an output sequence, wherein the first pattern corresponds to an inverted second pattern, wherein the second pattern is a byte pattern of dummy bytes the convolution interleaver would insert during an increase of the interleaver depth from D 2  to D 1 .