Title :
Reduced Complexity Decoder for Orthogonal Space-Time Codes When Using QAM Constellations and Multiple Receive Antennas
Author :
Enescu, Andrei Alexandru ; Ciochinã, Silviu ; Paleologu, Constantin
Author_Institution :
Fac. of Electron., Telecommun. & Inf. Technol., Univ. Politeh. of Bucharest, Bucharest, Romania
Abstract :
Space-time block coding represents a practical and pragmatic method to mitigate the fading effects and to increase the channel capacity, by using spatial diversity. The space-time coding techniques are still preferred in communication systems because of the very simple transmit coding rule and of the relative reduced complexity of the maximum likelihood (ML) receivers with respect to other coding methods (e.g., space-time trellis codes) or other MIMO (Multiple Input Multiple Output) algorithms (e.g., spatial multiplexing). One of the drawbacks when using space-time block codes is the increase in complexity at the ML receiver when increasing the number of transmit antennas and the number of constellation points. This paper deals with this issue and introduces a decoding algorithm applicable only for orthogonal space-time block codes. We show that this decoding algorithm reduces the search space dimension of a regular ML receiver, leading to significant complexity reduction for quadrature amplitude modulation (QAM) constellations. The algorithm is then extended to an arbitrary number of receive antennas, increasing the spatial diversity order.
Keywords :
Block codes; Channel capacity; Convolutional codes; Fading; MIMO; Maximum likelihood decoding; Quadrature amplitude modulation; Receiving antennas; Space time codes; Transmitting antennas; Alamouti code; maximum likelihood (ML) decoding; orthogonal space-time codes; spatial diversity;
Conference_Titel :
Digital Telecommunications (ICDT), 2010 Fifth International Conference on
Conference_Location :
Athens, TBD, Greece
Print_ISBN :
978-1-4244-7271-0
DOI :
10.1109/ICDT.2010.34