Component decoder and method thereof in mobile communication system

A decoding method at a receiver in a mobile communication system, comprising the steps of:

• calculating a plurality of BMs by binary computation a plurality of input symbols with all possible codewords;
• generating next PMs, reliability information, and a path selection bit at a time instant K by performing an add-compare-select operation on the BMs and previous PMs;
• outputting an ML state after a time period Ds from the time instant K based on a path selection bits, which is generated by the add-compare-select operation for the Ds period;
• delaying a LLRs, each LLR including reliability information and a corresponding path selection bit by the time Ds from the time instant K;
• updating Ds-delayed LLRsusing plurality of reliability information and path selection bits for DL period;
• and
• selecting an updated LLR value based on the ML state among the updated LLRs.

A decoding method at a receiver in a mobile communication system, comprising the steps of:

• calculating a plurality of BMs by using a plurality of input symbols with all possible codewords;
• generating next PMs, LLRs, each LLR including reliability information and a path selection bit at a time instant K by performing an add-compare-select operation on the BMs and previous PMs;
• receiving Ds number of path selection bits for a time period Ds from the time instant K and outputting an ML state value for the time instant Ds;
• and
• updating the LLRs using plurality of reliability information and path selection bits, which is generated for a time instant DL;
• and
• outputting an updated LLR selected based on the ML state value.

A turbo code decoder comprising:

• a BMC for calculating BMs by using a plurality of input symbols with all possible codewords;
• an ACS for receiving the BMs and previous PMs, which is generated at just previous ACS operation, and generating a plurality of path selection bits and plurality of reliability information at a first time instant;
• an ML state searcher for searching an ML state value representing an ML path using series of path selection bits, which is received from the ACS for a first time period;
• a LLR updater for updating a reliability information by using a series of path selection bits and plurality of reliability information for a second time period;
• and
• selector for selecting an updated reliability value by using the ML state value.

A turbo code decoding method comprising the steps of:

• calculating BMs by using a plurality of input symbols with all possible codewords;
• receiving the BMs and previous PMs, which is generated at just previous ACS operation;
• generating plurality of path selection bits and plurality of reliability information at a first time instant;
• searching an ML state value representing an ML path using series of path selection bits for a first time period;
• updating the reliability information by using a series of path selection bits and plurality of reliability information for a second time period;
• and
• selector for selecting an updated reliability value by using the ML state value.