Joint optimization in multi-user MIMO-OFDMA relay-enhanced cellular networks

• MIMO, OFDMA and cooperative relaying are the key technologies in future wireless communication systems. However, under the usage of these technologies, resource allocation becomes a more crucial and challenging task. In multi-user MIMO-OFDMA relay-enhanced cellular networks, we formulate the optimal instantaneous resource allocation problem including user group selection, path selection, power allocation, and subchannel scheduling to maximize system capacity. We first propose a low-complex resource allocation algorithm named CP-CP under constant uniform power allocation and then use a water-filling method named CP-AP to allocate power among transmitting antennas. Moreover, we solve the original optimization problem efficiently by using the Jensen's inequality and propose a modified iterative water-filling algorithm named AP-CP. Based on AP-CP, the AP-AP algorithm is proposed to allocate power adaptively not only among subchannels but also among multiple transmitting. Finally, we compare the performance of the four schemes. Our results show that allocating power among subchannels is more effective than among transmitting antennas if the average signal-to-noise radio of users is low, and vice versa. Furthermore, the AP-AP algorithm achieves the highest throughout especially for users near the cell edge.

Subject headings

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

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

Keyword

Cell edges

Cellular network

Cooperative relaying

Iterative water-filling algorithm

Jensen's inequality

Joint optimization

Key technologies

MIMO-OFDMA

Multi-user

Optimization problems

Path selection

Power allocations

Relay-enhanced

Resource allocation algorithms

Resource allocation problem

Signal to noise

Subchannels

System Capacity

Transmitting antenna

Uniform power allocations

User groups

Waterfilling

Wireless communication system

Algorithms

Antennas

Beamforming

Cellular neural networks

Communication systems

Global system for mobile communications

MIMO systems

Optimization

Resource allocation

Wireless networks

Wireless telecommunication systems

Frequency division multiple access

Publication and Content Type

ref (subject category)

kon (subject category)