公开(公告)号：DE69614772D1

公开(公告)日：2001-10-04

申请号：DE69614772

申请日：1996-06-10

Applicant: IBM

Inventor： HASSNER MARTIN AURELIANO ,  TAMURA TETSUYA ,  WINOGRAD SHMUEL

IPC: G11B20/10 ,  G11B20/14 ,  G11B20/18

Abstract: Parallel ML processing of an analog signal in a RLL-coded channel in which (1) vectors for a current state of the channel and the next state of the channel are computed using Walsh transform vector coefficients of the analog signal; (2) current state vectors and next state vectors and values of vectors precomputed in analog matched filters are used to generate vector scalar products which are compared against preselected threshold values for generating binary decision outputs that are used in digital sequential finite state machines to generate ML symbol decisions; and (3) ML symbol decisions are fed back and used to subtract the intersymbol interference value of the current state vector from the vector of the next state to transform the next state vector into an updated current state vector.

公开(公告)号：CA1111561A

公开(公告)日：1981-10-27

申请号：CA301231

申请日：1978-04-17

Applicant: IBM

Inventor： WINOGRAD SHMUEL

IPC: G06F17/14 ,  G06F15/34

Abstract: COMPUTER SYSTEM ARCHITECTURE FOR PERFORMING NESTED LOOP OPERATIONS TO EFFECT A DISCRETE FOURIER TRANSFORM A computer system architecture and method for performing the Discrete Fourier Transform on a set of N sampled input signals wherein N is chosen to be the product of a group of predetermined relatively prime factors (n1?n2?...?nL). The present architecture then proceeds to the solution of the Fourier transform via a unique nested loop solution method, wherein each loop is specifically related to each factor and wherein no multiplications are performed in the outer loops said method being further characterized by the fact that the system control is automatically passed to the next inner loop whenever a multiplication instruction is encountered. A unique predetermined sequence of operations which is unique to each factor (n?) is built into the system controls and automatic control means proceed from one sequence to another depending upon the factors (n) associated with a chosen N. The unique set of instruction sequences for each small factor of (n) is predicated upon a unique solution for the small Fourier transform matrix associated with said factor. Means are included in the system so that in all outer loops all addition operations required are performed on vector quantities and, in the single innermost loop, additions and multiplications are performed on scalar quantities. Means are additionally provided for determining composite coefficients to be used in multiplications occuring in the innermost loop, said composite coefficients comprising the product of the multiplication coefficient to be currently performed in the innermost loop as well as the coefficient essential with each pseudo multiply in each outermost loop currently involved in the current innermost loop computation. After all loop input adds, multiplications, and output adds have been performed the resultant output vector is the Fourier transform of the original input vector. In addition to the actual transform procedure an input vector reordering operation must be performed and an output vector reordering operation.