%0 Journal Article
%T Discrete Artificial Bee Colony for Computationally Efficient Symbol Detection in Multidevice STBC MIMO Systems
%A Saeed Ashrafinia
%A Muhammad Naeem
%A Daniel Lee
%J Advances in Artificial Intelligence
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/578710
%X A Discrete Artificial Bee Colony (DABC) is presented for joint symbol detection at the receiver in a multidevice Space-Time Block Code (STBC) Mutli-Input Multi-Output (MIMO) communication system. Exhaustive search (maximum likelihood detection) for finding an optimal detection has a computational complexity that increases exponentially with the number of mobile devices, transmit antennas per mobile device, and the number of bits per symbol. ABC is a new population-based, swarm-based Evolutionary Algorithms (EA) presented for multivariable numerical functions and has shown good performance compared to other mainstream EAs for problems in continuous domain. This algorithm simulates the intelligent foraging behavior of honeybee swarms. An enhanced discrete version of the ABC algorithm is presented and applied to the joint symbol detection problem to find a nearly optimal solution in real time. The results of multiple independent simulation runs indicate the effectiveness of DABC with other well-known algorithms previously proposed for joint symbol detection such as the near-optimal sphere decoding, minimum mean square error, zero forcing, and semidefinite relaxation, along with other EAs such as genetic algorithm, estimation of distributions algorithm, and the more novel biogeography-based optimization algorithm. 1. Introduction Multi-Input Multi-Output (MIMO) communication systems can offer spatial diversity gains in the fading channels and have significantly higher channel capacity than the Single-Input Single-Output (SISO) systems for the same total transmission power and bandwidth [1, 2]. The system proposed in this paper comprises of one receiving station and multiple transmitting devices. The receiver¡¯s front end has multiple antennas, and each transmitting device has multiple transmit antennas. Employing the Space Time Block-Code (STBC) is realized to increase the capacity of MIMO systems and consequently improves data throughput and spectral efficiency [3]. Multiantenna systems are widely used because of their ability of dramatically increasing the channel capacity in fading channels [4]. Each transmit device uses an STBC; the receiver side performs the joint signal detection. Such a system is referred to as a multidevice (MD) STBC-MIMO system. Generally in an MD-STBC-MIMO system, the number of receive antennas is typically smaller than the cumulative number of transmit antennas used by all transmitting devices in the system. An example of MD-STBC-MIMO, with a smaller number of antennas at the base station or access point, would be the uplink
%U http://www.hindawi.com/journals/aai/2013/578710/