Caching piggyback information for efficient index code transmission

The index coding problem is a fundamental transmission problem arising in content distribution and wireless networks. Traditional approach to solve this problem is to find heuristic/ approximation minimum clique partition solution on an appropriately mapped graph of the index coding problem. In this paper we study index code for unicast data flow for which we propose updated clique index coding (UCIC) scheme, UCIC piggybacks additional information in the coded symbol such that an unsatisfied client can update its cache. We show that UCIC has higher coding gain than previously proposed index coding schemes, and it is optimal for those instances where index code of minimum length is known.