Subcarrier Group Assignment for MC-CDMA Wireless Networks

Chen

2009 IEEE 70th Vehicular Technology Conference Fall

2009

Motivated by the increasing popularity of multicarrier code division multiple access (MC-CDMA) systems, this letter studies the throughput maximization of MC-CDMA as a downlink multi-carrier multiple-access scheme and presents the theoretical analysis for the optimal solution to throughput optimization problem of downlink MC-CDMA systems. Then, a low-complexity allocation method is proposed with negligible throughput loss. Finally, several resource allocation principles are presented.

Section: Maximization Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Throughput Maximization of Downlink MC-CDMA Systems

Chen

2009 IEEE 70th Vehicular Technology Conference Fall

2009

“…Due to the simultaneous transmissions, sub-carriers interfere with each other and limit the network performance. To achieve robustness and spectral efficiency in MC-CDMA system over multipath fading channels, the technology is ruled by two main functions; power allocation [2] over the sub carriers and sub carrier group assignment [3]. Power allocation is the scheme by which users share the power available at the serving base station.…”

Section: Introductionmentioning

confidence: 99%

Power Control and Sub Carrier Grouping for MCCDMA-MIMO Using Water Filling Game Theory

Sundhar¹,

Dananjayan²

2014

IJCEE

Abstract-The capacity enhancement in Multi Carrier Code Division Multiple Access (MC-CDMA) technique with multiple antennas at both the transmitter and the receiver is achieved by restricting interference noise through power control method at transmitter. Due to time varying nature of the channel, channel fading is not identical to all sub carriers. So, the allocation of sub carriers to the users according to the instantaneous Channel State Information (CSI) is also improves the capacity of the MCCDMA system. In this paper, The maximization of capacity in MCCDMA-MIMO system is achieved through dynamic allocation of sub carriers to each user and power allocation using water filling game theory subject to the constrain of total power at transmitter. The water filling algorithm distributes power among all users with the help of SINR that is received by the transmitter instead of getting full CSI. The sub carrier group assignment is implemented by selecting best sub carriers with maximum Signal to Interference and Noise Ratio (SINR) value and user's rate requirements. The performances of capacity improvements and outage probability reduction in MCCDMA-MIMO are analyzed with various diversity sizes (SISO, 22, 44).

“…Due to the simultaneous transmissions; sub-carriers interfere with each other and limit the wireless network performances. To achieve robustness and spectral efficiency in MCCDMA system over multipath fading channels, the technology is ruled by two main functions; power allocation [2] over the sub carriers and sub carrier group assignment [3]. Power allocation is the scheme by which users share the power available at the serving base station.…”

Section: Introductionmentioning

confidence: 99%

Performance Enhancement of Grouped MCCDMA-MIMO System through Power Control Using Water Filling Game Theory under Imperfect Channel State Condition

Arumugam¹,

Dananjayan²

2014

IJCNS

Continuous increase in demand of wireless services such as voice, data and multimedia is fueling the need of spectrally efficient techniques in communication networks. The MCCDMA-MIMO, a system of Multi Carrier Code Division Multiple Access (MCCDMA) technique with multiple antennas at both the transmitter and receiver gets benefits of ability to adopt multiple access capability from MCCDMA technique, achieves high data rate from MIMO concepts and becomes a very attractive multiple access technique for the future wireless communication systems. But, the wireless channels in MCCDMA-MIMO networks are known to display significant variations across active users' subcarriers as well as among subcarriers of the same user due to simultaneous spectrum utilization. This leads to the undesirable Multiple-Access Interference (MAI) and Inters Carrier Interference (ICI), accordingly degrades the performance of the system. So, the interference mitigation methodology in the MCDMA-MIMO system has received a lot of attention in next generation mobile environment. The power control and sub carrier grouping methods have been long standing open solutions for capacity enhancement. The strategic choice of assigning the transmission power to each individual subcarrier in the MCCDMA-MIMO system is subjected to the knowledge of Channel State Information (CSI), which usually becomes imperfect due to the time varying nature of the channels. The goal of this paper is to allocate proper power to sub-carriers of MCCDMA-MIMO system by playing water filling game theory against the CSI errors to improve the performance of the system.