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A new method for the solution of hybrid analog digital beamforming problems

Amini, E ; Sharif University of Technology | 2020

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  1. Type of Document: Article
  2. DOI: 10.1002/oca.2636
  3. Publisher: John Wiley and Sons Ltd , 2020
  4. Abstract:
  5. By going to millimeter wave (mmWave) we can use large scale MIMO due to short mmWave wavelength to overcome path loss by using beamforming to focus power of signal to the receiver. System structure of mmWave band is different with conventional MIMO because of large scale MIMO which is leading to use many RF-chains. For this reason Hybrid structure have been proposed for large Scale MIMO. By going to Hybrid structure a new issue has been created with phase shifter constraint. In this paper we propose a novel solution to make a hybrid precoding and combing to reach high spectral efficiency. Our problem includes a maximizing Frobenius norm of multiplying five complex matrices. As constraints, all elements of some matrices must have unit norm, and also the multiplication of some matrices must have a specific Frobenius norm. A novel solution is proposed for the problem, which is gained in two steps. At the first step, we propose a new decomposition usable for kind of complex matrices which could lead to reduce the dimension of the objective function, and eliminating constraints completely and in the second step, we propose an iterated algorithm for the resulting problem. By proposing another novel technique, we show that in each iteration, the optimal problem is equivalent to a quadratic optimal problem with limitations on the vector norm, and as a result, an optimal problem is obtained quickly. Moreover, some other real examples are included to demonstrate the usefulness and effectiveness of the proposed algorithm. © 2020 John Wiley & Sons, Ltd
  6. Keywords:
  7. Hybrid analog digital beamforming ; Matrix decomposition ; Maximizing Frobenius norm ; Quadratic optimal problem ; Quadratization technique ; Beamforming ; Millimeter waves ; Quadratic programming ; Signal receivers ; Digital beam forming ; High spectral efficiency ; Millimeter waves (mmwave) ; Novel techniques ; Objective functions ; Optimal problems ; Quadratic-optimal ; System structures ; Iterative methods
  8. Source: Optimal Control Applications and Methods ; Volume 41, Issue 5 , 2020 , Pages 1735-1748
  9. URL: https://onlinelibrary.wiley.com/doi/abs/10.1002/oca.2636