The Minimum Decoding Delay of Maximum Rate Complex Orthogonal Space–Time Block Codes2007
AbstractThe growing demand for efficient wireless transmissions over fading channels motivated the development ofspace-time block codes. Space-time block codes built from generalized complex orthogonal designs are particularly attractive because the orthogonality permits a simple decoupled maximum-likelihood decodingalgorithm while achieving full transmit diversity. The two main research problems for these complex orthogonalspace-time block codes (COSTBCs) have been to determine for any number of antennas the maximum rate andthe minimum decoding delay for a maximum rate code. The maximum rate for COSTBCs was determined by Liang in 2003. This paper addresses the second fundamental problem by providing a tight lower bound on the decodingdelay for maximum rate codes. It is shown that for a maximum rate COSTBC for 2m - 1 or 2m antennas, a tight lower bound on decoding delay is r = (m-1 2m) . This lower bound on decoding delay is achievable when thenumber of antennas is congruent to 0, 1, or 3 modulo 4. This paper also derives a tight lower bound on thenumber of variables required to construct a maximum rate COSTBC for any given number of antennas. Furthermore, it is shown that if a maximum rate COSTBC has a decoding delay of r where r < r les 2r, then r=2r. This is used to provide evidence that when the number of antennas is congruent to 2 modulo 4, the best achievable decoding delay is 2(m-1 2m_).
Citation InformationSarah Spence Adams, Nathaniel Karst and Jonathan Pollack. "The Minimum Decoding Delay of Maximum Rate Complex Orthogonal Space–Time Block Codes" (2007)
Available at: http://works.bepress.com/sarah_spence_adams/9/