QRD based tree search data detection for MIMO communication systems

Due to the capacity achievable, multiple-input/multiple-output (MIMO) systems has gained popularity in recent years. While several data detection algorithms are available for MIMO systems, simple algorithms usually perform unsatisfactorily, while more complex ones are infeasible for hardware implementation. In this paper, we compare two QRD based tree search algorithms which can be likely candidates for implementation purposes due to their relatively low computational complexity. The QRD-M algorithm proposed in (J Yue, et al, 2003) yields near-M L performance while only requiring a fraction of the computational complexity of an ML receiver. The QRD-stack algorithm displays similar performance. The performance of both QRD-M and QRD-stack algorithms are compared and while both algorithms achieve near-ML performance, the QRD-stack algorithm is shown to be more efficient and has a much lower computational complexity as compared to QRD-M.