A New Beamformer Design Method for Multi-Group Multicasting by Enforcing Constructive Interference

2018-08-07
Demir, Özlem Tuğfe
Tuncer, Temel Engin
In this paper, we propose a new multi-group multi-cast beamforming design method for phase shift keying (PSK) modulated signals. Quality of service (QoS)-aware optimization is considered where the aim is to minimize transmission power of multiple-antenna base station under the QoS constraints of single-antenna users. In this paper, we show that symbol-level beamforming scheme proposed in the literature is not an effective design method for multi-group multicasting and modify it using rotated constellation approach in order to reduce transmission power. Proposed method enforces the known interference in a constructive manner such that the received symbol at each user is inside the correct decision region for any set of symbols. Hence, designed beamformers can be utilized throughout a transmission-frame rather than symbol-by-symbol basis. An alternating direction method of multipliers (ADMM) algorithm is presented for the proposed design problem and closed-form update equations are derived for the steps of the ADMM algorithm. Simulation results show that the proposed method decreases the transmission power significantly compared to the conventional and symbol-level beamforming.

Suggestions

Improved ADMM-Based Algorithm for Multi-Group Multicast Beamforming in Large-Scale Antenna Systems
Demir, Özlem Tuğfe; Tuncer, Temel Engin (2018-08-07)
In this paper, we consider beamformer design for multi-group multicasting where a common message is transmitted to the users in each group. We propose a novel effective alternating direction method of multipliers (ADMM) formulation in order to reduce the computational complexity of the existing state-of-the-art algorithm for multi-group multicast beamforming with per-antenna power constraints. The proposed approach is advantageous for the scenarios where the dimension of the channel matrix is less than the ...
Novel SIE Implementations for Efficient and Accurate Electromagnetic Simulations of Zero-index Materials
Ibili, H.; Koyaz, Y.; Ozmu, U.; Karaosmanoglu, B.; Ergül, Özgür Salih (2019-01-01)
We present novel surface-integral-equation formulations for efficient and accurate iterative solutions of electromagnetic problems involving zero-index (ZI) and near-zero-index (NZI) materials. When applied to materials with small permittivity and/or permeability values, conventional implementations employing traditional formulations tend to become inefficient, inaccurate, or both. Such numerical issues arise mainly due to low-frequency breakdowns related to inner problems, as well as due to deteriorating b...
A Nonlinear Detector for Uplink SC-FDE mm-Wave Hybrid Massive MIMO under Hardware Impairments
Salman, Murat Babek; Güvensen, Gökhan Muzaffer (2021-06-01)
In this paper, we propose a detector structure for fully connected hybrid massive MIMO systems with transceiver impairments at user equipments. In literature, memoryless compensation of nonlinear effects at the receiver side is recently proposed for systems employing frequency domain equalization. However, in these studies, the system model is restricted to be symbol sampled, where pulse shaping and fractional delays in channel impulse response (CIR) are not taken into consideration. However, memory effects...
Development of a 2d discrete turbulent adjoint solver using automatic differentiation
Kaya, Halil; Tuncer, İsmail Hakkı; Tiftikci, Hakan (null; 2019-09-18)
This paper presents an implementation of discrete adjoint solver using an automatic differentiation tool for a two-dimensional Reynolds Averaged Navier-Stokes (RANS) finite volume solver. Moreover, automatic differentiation tool is also utilized calculating flux Jacobian required by implicit finite volume solver. The developed RANS adjoint solver is computationally efficient and accurate. In the present implementation, the time required for the calculation of adjoint variables is comparable to the time requ...
An adaptive, energy-aware and distributed fault-tolerant topology-control algorithm for heterogeneous wireless sensor networks
Deniz, Fatih; Bagci, Hakki; KÖRPEOĞLU, İBRAHİM; Yazıcı, Adnan (2016-07-01)
This paper introduces an adaptive, energy-aware and distributed fault-tolerant topology control algorithm, namely the Adaptive Disjoint Path Vector (ADPV) algorithm, for heterogeneous wireless sensor networks. In this heterogeneous model, we have resource-rich supernodes as well as ordinary sensor nodes that are supposed to be connected to the supernodes. Unlike the static alternative Disjoint Path Vector (DPV) algorithm, the focus of ADPV is to secure supernode connectivity in the presence of node failures...
Citation Formats
Ö. T. Demir and T. E. Tuncer, “A New Beamformer Design Method for Multi-Group Multicasting by Enforcing Constructive Interference,” 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/54057.