Multigroup-Decodable STBCs from Clifford Algebras

A Space-Time Block Code (STBC) in K symbols (variables) is called g-group decodable STBC if its maximumlikelihood decoding metric can be written as a sum of g terms such that each term is a function of a subset of the K variables and each variable appears in only one term. In this paper we provide a general structure of the weight matrices of multi-group decodable codes using Clifford algebras. Without assuming that the number of variables in each group to be the same, a method of explicitly constructing the weight matrices of full-diversity, delay-optimal g-group decodable codes is presented for arbitrary number of antennas. For the special case of Nt = 2a we construct two subclass of codes: (i) A class of 2a-group decodable codes with rate a 2(a-1) , which is, equivalently, a class of Single-Symbol Decodable codes, (ii) A class of (2a-2)-group decodable with rate (a-1) 2(a-2) , i.e., a class of Double-Symbol Decodable codes. Simulation results show that the DSD codes of this paper pe...

• Type: Journal
• Year: 2006
• Where: CORR
• Authors: Sanjay Karmakar, B. Sundar Rajan
• Keywords: CORR 2006, Decodable Codes, Education, Space-time Block Code, Weight Matrices