Near optimum power control and precoding under fairness constraints in network MIMO systems

• We consider the problem of setting the uplink signal-to-noise-and- interference (SINR) target and allocating transmit powers for mobile stations in multicell spatial multiplexing wireless systems. Our aim is twofold: to evaluate the potential of such mechanisms in network multiple input multiple output (MIMO) systems, and to develop scalable numerical schemes that allow real-time near-optimal resource allocation across multiple sites. We formulate two versions of the SINR target and power allocation problem: one for maximizing the sum rate subject to power constraints, and one for minimizing the total power needed to meet a sum-rate target. To evaluate the potential of our approach, we perform a semianalytical study in Mathematica using the augmented Lagrangian penalty function method. We find that the gain of the joint optimum SINR setting and power allocation may be significant depending on the degree of fairness that we impose. We develop a numerical technique, based on successive convexification, for real-time optimization of SINR targets and transmit powers. We benchmark our procedure against the globally optimal solution and demonstrate consistently strong performance in realistic network MIMO scenarios. Finally, we study the impact of near optimal precoding in a multicell MIMO environment and find that precoding helps to reduce the sum transmit power while meeting a capacity target.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Kommunikationssystem (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Communication Systems (hsv//eng)

Nyckelord

Augmented Lagrangians

Convexification

Fairness constraints

Mathematica

Mobile station

Multicell

Multiple-input-multiple-output systems

Near optimum

Numerical scheme

Numerical techniques

Optimal solutions

Penalty function methods

Power allocations

Power constraints

Precoding

Real-time optimization

Semi-analytical

Spatial multiplexing

Sum-rate

Total power

Transmit power

Wireless systems

Communication channels (information theory)

Fading channels

Multiplexing

Optimization

Real time systems

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)