Patent ID: 6940928
Filing Date: 2005-09-06
Classification: H03M,H04L

Abstract:
1. A method for computing extrinsic likelihood values in a soft in soft out (SISO) decoder the method comprising: accepting a block of channel metrics and a priori values; dividing the block of channel metrics and a priori values into sub blocks accepting an nth channel metric and an nth a priori value into an alpha (α) computer; computing an nth α value from the nth channel metric and the nth a priori value using the nth α value to compute the (n+1)th a value; pushing α values corresponding to the beginning of a sub block on a checkpoint stack until a beginning of the last sub block is reached; pushing each of the α values of the final sub block on the checkpoint stack; popping each of the α values of the last sub block from the checkpoint stack and combining them with beta (β) values to form extrinsic likelihood values.