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公开(公告)号：CA1129030A
公开(公告)日：1982-08-03
申请号：CA354508
申请日：1980-06-20
Applicant: IBM
Inventor： BAHL LALIT R , COCKE JOHN , CULLUM CLIFTON D JR , HAGENAUER JOACHIM
Abstract: ERROR CORRECTION ON BURST CHANNELS BY SEQUENTIAL DECODING A sequential decoder for error correction on burst and random noise channels using convolutionally encoded data. The decoder interacts with a deinterleaver which time demultiplexes data from a data channel from its time multiplexed form into a predetermined transformed order. The decoder includes a memory for storing a table of likelihood values which are derived from known error statistics about the data channel such as the probabilities of random errors and burst errors, burst error severity and burst duration. The decoder removes an encoded subblock of data from the deinterleaver and enters it into a replica of the convolutional encoder which calculates a syndrome bit from a combination of the presently received subblock together with a given number of previous subblocks. The syndrome bit indicates if the current assumption of the path through the convolutional tree is correct. Where there is no error in the channel, then the received sequence is a code word and the syndrome bit indicates that the correct path in the convolution tree is taken. For each received bit, an indicator bit is calculated which is a function of the difference between the current path and the received sequence. The sequential decoder employs the syndrome bit together with burst indicator bits to calculate a table address in a table of likelihood values and error pattern values. The likelihood value is used to update a total likelihood of error value and the error pattern value is used to change the received subblock of data. YO975-038
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公开(公告)号：CA1105622A
公开(公告)日：1981-07-21
申请号：CA282620
申请日：1977-07-13
Applicant: IBM
Inventor： CULLUM CLIFTON D JR
Abstract: GAP ELIMINATION IN MEMORY DATA ACCESSION This invention relates to the reduction of gaps in the flow of data accessed in a synchronous serial storage serial communicating data processing memory by the provision of access storage capability at each storage location.
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公开(公告)号：CA1128205A
公开(公告)日：1982-07-20
申请号：CA338281
申请日：1979-10-24
Applicant: IBM
Inventor： CULLUM CLIFTON D JR , KEEFE GEORGE E , KRYDER MARK H , LIN YEONG S
Abstract: MAGNETIC BUBBLE DOMAIN CHIP WITH ENHANCED PROPAGATION MARGINS In magnetic bubble domain chips using layers of crystalline material having in-plane magnetization for propagation, hard bubble suppression, etc., asymmetric propagation often results due to crystalline anisotropies in the layer of in-plane magnetization. In these chips, different propagation margins result for propagation in different directions with respect to the crystalline axes of the in-plane layer. In the present magnetic chip, a plurality of shift registers is provided for movement of bubble domains in a plurality of directions, all of which provide good propagation margins. The registers are aligned in particular directions with respect to the directions of easy stripout of bubble domains in order to avoid the problem of asymmetric propagation. Examples are shown using ion implanted contiguous element propagation patterns organized in a major/minor loop type of storage organization. Y0978-047
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