With rapid increase in demand for higher data rates, multiple-input multiple-output (MIMO) wireless
communication systems are getting increased research attention because of their high capacity achieving
capability. However, the practical implementation of MIMO systems rely on the computational complexity
incurred in detection of the transmitted information symbols. The minimum bit error rate performance
(BER) can be achieved by using maximum likelihood (ML) search based detection, but it is
computationally impractical when number of transmit antennas increases. In this paper, we present a
low-complexity hybrid algorithm (HA) to solve the symbol vector detection problem in large-MIMO systems.
The proposed algorithm is inspired from the two well known bio-inspired optimization algorithms
namely, particle swarm optimization (PSO) algorithm and ant colony optimization (ACO) algorithm. In the
proposed algorithm, we devise a new probabilistic search approach which combines the distance based
search of ants in ACO algorithm and the velocity based search of particles in PSO algorithm. The motivation
behind using the hybrid of ACO and PSO is to avoid premature convergence to a local solution and
to improve the convergence rate. Simulation results show that the proposed algorithm outperforms the
popular minimum mean squared error (MMSE) algorithm and the existing ACO algorithms in terms of
BER performance while achieve a near ML performance which makes the algorithm suitable for reliable
detection in large-MIMO systems. Furthermore, a faster convergence to achieve a target BER is observed
which results in reduction in computational efforts.