Constructive Multiuser Interference in Symbol Level Precoding for the MISO Downlink Channel

This paper investigates the problem of interference among the simultaneous multiuser transmissions in the downlink of multiple antennas systems. Using symbol level precoding, a new approach towards the multiuser interference is discussed along this paper. The concept of exploiting the interference between the spatial multiuser transmissions by jointly utilizing the data information (DI) and channel state information (CSI), in order to design symbol-level precoders, is proposed. In this direction, the interference among the data streams is transformed under certain conditions to useful signal that can improve the signal to interference noise ratio (SINR) of the downlink transmissions. We propose a maximum ratio transmission (MRT) based algorithm that jointly exploits DI and CSI to glean the benefits from constructive multiuser interference. Subsequently, a relation between the constructive interference downlink transmission and physical layer multicasting is established. In this context, novel constructive interference precoding techniques that tackle the transmit power minimization (min power) with individual SINR constraints at each user's receivers is proposed. Furthermore, fairness through maximizing the weighted minimum SINR (max min SINR) of the users is addressed by finding the link between the min power and max min SINR problems. Moreover, heuristic precoding techniques are proposed to tackle the weighted sum rate problem. Finally, extensive numerical results show that the proposed schemes outperform other state of the art techniques.Comment: Submitted to IEEE Transactions on Signal Processin

Resource Allocation Algorithm for MU-MIMO Systems with Double-Objective Optimization under the Existence of the Rank Deficient Channel Matrix

© 2013 IEEE. This paper proposes a double-objective optimization resource allocation algorithm for the multi-user multiple-input/multiple-output (MU-MIMO) system in the general wireless environment and demonstrates the maximum number of simultaneously supportable users and the achievable bit rates of users in the general wireless environment with full rank and rank-deficient channels. The double-objective joint optimization algorithm proposed in this paper simultaneously optimizes energy efficiency and system throughput by user selection and power allocation. On this basis, the proposed algorithm guarantees the different QoS requirements of various services, including rate requirements and delay requirements