High-rate, Multi-Symbol-Decodable STBCs from Clifford Algebras

13 years 4 months ago

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It is well known that Space-Time Block Codes (STBCs) obtained from Orthogonal Designs (ODs) are singlesymbol-decodable (SSD) and from Quasi-Orthogonal Designs (QODs) are double-symbol decodable. However, there are SSD codes that are not obtainable from ODs and DSD codes that are not obtainable from QODs. In this paper a method of constructing g-symbol decodable (g-SD) STBCs using representations of Clifford algebras are presented which when specialized to g = 1, 2 gives SSD and DSD codes respectively. For the number of transmit antennas 2a the rate (in complex symbols per channel use) of the g-SD codes presented in this paper is a+1−g 2a−g . The maximum rate of the DSD STBCs from QODs reported in the literature is a 2a−1 which is smaller than the rate a−1 2a−2 of the DSD codes of this paper, for 2a transmit antennas. In particular, the reported DSD codes for 8 and 16 transmit antennas offer rates 1 and 3/4 respectively whereas the known STBCs from QODs offer only 3/4 and 1/2...

Sanjay Karmakar, B. Sundar Rajan

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