Multi-antenna transmission using ESPAR with peak power constraints

Electronically steerable parasitic array radiator (ESPAR) technology provides multi-antenna transmission with a single radio frequency (RF) unit. In order to achieve stable transmission using an ESPAR antenna (EA), two approaches have been proposed in literature. One is to increase the self-resistance of an EA, the other is to transmit signals closely approximating the actual signals that keep the EA stable. In both approaches, no constraint on the transmission power of an EA was considered. This is not the case in actual systems, as the practical power amplifier normally has limited peak power. Taking into account the limited power availability, an optimization problem is formulated with the objective to minimize the MSE between the currents corresponding to the ideal and the approximate transmission signals. The non-convex problem is solved analytically by coordination transformation and a novel algorithm is proposed. It is shown that the system employing the proposed transmission scheme gives similar performance to that of a standard multiple antenna system, especially at low SNRs. In addition, it is shown that increasing the self-resistance of an EA to achieve stability is highly power inefficient.

[1]  Tharmalingam Ratnarajah,et al.  Achieving Arbitrary Signals Transmission Using a Single Radio Frequency Chain , 2015, IEEE Transactions on Communications.

[2]  Josef A. Nossek,et al.  Toward a Circuit Theory of Communication , 2010, IEEE Transactions on Circuits and Systems I: Regular Papers.

[3]  D. Eberly.  Distance from a Point to an Ellipse, an Ellipsoid, or a Hyperellipsoid , 2006 .

[4]  Constantinos B. Papadias,et al.  Arbitrary Precoding with Single-Fed Parasitic Arrays: Closed-Form Expressions and Design Guidelines , 2014, IEEE Wireless Communications Letters.

[5]  R. Bansal,et al.  Antenna theory; analysis and design , 1984, Proceedings of the IEEE.

[6]  Tharmalingam Ratnarajah,et al.  Energy efficient cloud radio access network with a single RF antenna , 2016, 2016 IEEE International Conference on Communications (ICC).

[7]  Titus K. Y. Lo.  Maximum ratio transmission , 1999, IEEE Trans. Commun..

[8]  Ralf R. Müller,et al.  Load modulated arrays: a low-complexity antenna , 2016, IEEE Communications Magazine.

[9]  Roger F. Harrington,et al.  Reactively controlled directive arrays , 1978 .

[10]  T. Ohira,et al.  Electronically steerable parasitic array radiator antenna , 2004 .

[11]  Stephen P. Boyd,et al.  Convex Optimization , 2004, Algorithms and Theory of Computation Handbook.

[12]  R. Kaul,et al.  Microwave engineering , 1989, IEEE Potentials.

[13]  Warren L. Stutzman,et al.  Array antenna pattern modeling methods that include mutual coupling effects , 1993 .

[14]  Bo Han,et al.  MIMO over ESPAR with 16-QAM Modulation , 2013, IEEE Wireless Communications Letters.