The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 22, 2003
Filed:
Dec. 07, 1999
Ali S. Khayrallah, Apex, NC (US);
Gregory E. Bottomley, Cary, NC (US);
Ravinder David Koilpillai, Apex, NC (US);
Kambiz Zangi, Durham, NC (US);
Ericsson Inc., Research Triangle Park, NC (US);
Abstract
A reduced search symbol estimation algorithm includes a forward recursion, a backward recursion, and a combining step. To reduce complexity, during the forward and backward recursions, the number of survivor states retained at each stage is less than the total number of states of the trellis. The survivor states are selected from a group of candidate states, that are connected by branches to survivors from the previous stage of the recursion. The decoder compares the accumulated path metrics for each candidate state and retains a specified number of states that is less than the total possible number of states. For the forward recursion, the retained states or survivor states, denoted as Q , are stored along with the corresponding state metrics. For the backward recursion, the retained states, denoted as R , are stored along with the corresponding state metrics. During the combining step, the computation of a soft value is restricted to branches (s′,s) connecting survivor states s′ and s in the forward and backward recursions respectively.