Parallel Resource Allocation and Subcarrier Assignment for Downlink OFDMA

ABSTRACT

Orthogonal frequency division multiple access technique has attracted much attention for broadband wireless access in the fourth generation and fifth generation wireless communication systems. To achieve a high data rate, communication systems require proper resource allocation and subcarrier assignment (RASA). This demands sophisticated signal processing algorithms which are computationally complex. One of the possible solutions to this lies in the parallel processing of computationally intensive algorithms, to speedup the processes. This paper presents a parallel implementation of the Hungarian algorithm for subcarrier assignment and proposes a parallel RASA algorithm for resource and subcarrier assignment problems. The proposed RASA's algorithm implementation demonstrates superior performance in terms of execution time (complexity) and fairness ratio in comparison to Hungarian and amplitude craving greedy algorithms. The complexity in terms of an execution time of Hungarian and RASA algorithms are compared with a single thread and four threads implementation under open multi-processing environment.

KEYWORDS:

• Hungarian algorithm
• OFDMA
• OpenMP
• RASA
• Resource allocation
• Subcarrier assignment
• 4G
• 5G

ACKNOWLEDGEMENTS

Authors like to thank Instituto Superior Técnico, Lisboa, National Institute of Technology (NIT), Rourkela, India and ERASMUS MUNDUS NAMASTE project committee to support this mobility.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

ORCID

Satyendra Singh Yadav  http://orcid.org/0000-0002-7891-6997

Paulo Alexandre Crisóstomo Lopes  http://orcid.org/0000-0002-9045-0413

Sarat Kumar Patra  http://orcid.org/0000-0002-6188-1302

Notes

1. ZEROS is a variable size vector, the size of the this vector depends on the number of zeros found after step 1 and which are found during matrix compression stage.

2. This is just a default assignment of $|m_u|$ subcarriers obtained from BARE algorithm to respective user u. This algorithm is used as a reference to Hungarian and RASA algorithm. Using the default assignment in $\mathrm{HR}$ (20(20) $\mathrm{HR}={\left[\begin{array}{cccc}1.5& 1.8& 2.1& 1.2\\ 2.2& 1.6& 1.2& 1.4\\ 2.2& 1.6& 1.2& 1.4\\ 2.2& 1.6& 1.2& 1.4\end{array}\right]}_{N\times N}.$(20) ), the 1st subcarrier will be assigned to user 1 and remaining 3 subcarriers will be assigned to user 2.

Additional information

Funding

This work was supported by national funds through Fundação para a Ciência e a Tecnologia (FCT), Portugal with reference UID/CEC/50021/2013.

Notes on contributors

Satyendra Singh Yadav

Satyendra Singh Yadav was born in Tikamgarh (India) in 1991. He received his Bachelor of Engineering in electronics and communication from RITS-Bhopal, affiliated to Rajiv Gandhi Proudyogiki Vishwavidyalaya (RGPV) a State University of Madhya Pradesh (India), in 2012. In 2012 he joined National Institute of Technology, Rourkela (India), for he is working towards the PhD degree. He was with Instituto de Engenharia de Sistemas e Computadores Investigação e Desenvolvimento (INESC-ID), Instituto Superior Técnico, Lisbon, Portugal, under India-EU NAMASTE Mobility Project for the period of 9 months. His research interests include parallel algorithms for wireless communications systems as well as graphics processing unit (GPU) computing. Since 2014, he is a student member of IEEE.

Paulo Alexandre Crisóstomo Lopes

Paulo Alexandre Crisóstomo Lopes was born in Lisbon, Portugal, in 1974. He received the PhD degree in electrical engineering from Instituto Superior Tecnico (IST), Lisbon, in 2003. Currently, he is an Assistant Professor at IST and a Researcher at Instituto de Engenharia de Sistemas e Computadores Investigação e Desenvolvimento (INESC-ID), Lisbon. His current research interests are MIMO communications for 5G systems, Power Line Communications, Active Noise Control, Computer Architectures and Parallel Computing.Email: [email protected]

Sarat Kumar Patra

Sarat Kumar Patra received Bsc (engg) in electronics and telecommunication engg and MSc (engg) in electronics system and communication specialization from UCE Burla and NIT Rourkela (Formerly known as REC Rourkela), respectively. He received PhD from University of Edinburgh, UK in 1998. He has been with National Institute of Technology, Rourkela since 1989. His research interests include adaptive signal processing, fuzzy systems, wireless communication and related fields. Prof Patra is a life member of the Institution of Electronic and Telecommunication Engineers (IETE), India; Indian Society of Technical Education, Institute of Engineers, India; and Computer Society of India. He is also a senior member of IEEE since 2007. Currently, he is serving as a Director of Indian Institute of Information Technology, Vadodara, Gujrat–India. Prof Patra had supervised a large number of PhDs and published more than 165 papers in journals and conference proceedings. Email: [email protected]