International Journal of Wireless and Microwave Technologies (IJWMT)
IJWMT Vol. 4, No. 1, 8 Jan. 2014
Cover page and Table of Contents: PDF (size: 809KB)
Interference Mitigation Techniques for Spectral Capacity Enhancement in GSM Networks
Full Text (PDF, 809KB), PP.20-49
Views: 0 Downloads: 0
Author(s)
Ahmed M. Alaa
1,*
Hazim Tawfik
1
Index Terms
Random Frequency Hopping (FH), Power Control (PC), Discontinuous Transmission (DTX), Interference Diversity, Frequency diversity, Spectral Capacity
Abstract
Random Frequency Hopping (FH) is a key feature of GSM networks that allows for capacity enhancement. The increased co-channel interference experienced in networks with tight frequency reuse schemes can be mitigated by adopting frequency hopping. Frequency hopping diversifies the interference signals over sparse transmitted bursts. This effect is called Interference Diversity. Interference Diversity allows the Forward Error Correcting codes (FEC) to easily correct the corrupted bits. Thus, frequency hopping allows the network operator to use a tighter frequency reuse scheme without exhibiting higher levels of co-channel interference.
Discontinuous Transmission (DTX) is another interference mitigation method that utilizes the user’s silence frames to reduce the transmitted power, while Power Control (PC) links the transmitted handset power with its relative distance from the Base Station (BTS). In this work, we study the impact of random FH, DTX and PC on the Spectral Capacity of GSM cellular networks by means of combined link level and system level simulation. It is shown that a spectral capacity gain is obtained in a 3/9 reuse scheme that deploys PC, DTX and FH compared to a conventional 4/12 reuse scheme.
Cite This Paper
Ahmed M. Alaa, Hazim Tawfik,"Interference Mitigation Techniques for Spectral Capacity Enhancement in GSM Networks", IJWMT, vol.4, no.1, pp.20-49, 2014. DOI: 10.5815/ijwmt.2014.01.03
Reference
[1] Theodore S. Rappaport, “Wireless Communications: Principles and Practice”, Pearson, 2nd edition, 2009, p 41.
[2] Thomas Toftegaard Nielsen, Jeroen Wigard, “Performance Enhancements in Frequency Hopping GSM Network”, Springer, 2000, pp 187 – 207.
[3] GSM 05.02, “Wireless Multiplexing and multiple access on the radio path”, ETSI, 1996.
[4] Stefan Briick, “Modelling Interference Diversity in GSM Networks”, Vehicular Technology Conference, 2000. IEEE VTS-Fall VTC 2000. 52nd, pp 459 – 466.
[5] Hikan Olofsson, Jonas Naslund, Johan Skold, “Interference Diversity Gain in Frequency Hopping GSM”, Vehicular Technology Conference, 1995 IEEE 45th , pp 102-106.
[6] Jeroen Wigard and Preben Mogensen, “A Simple Mapping from C/I to FER and BER for a GSM Type Air-Interface”, Personal, Indoor and Mobile Radio Communications, 1996. PIMRC’96. Seventh IEEE International Symposium on, pp 78 – 82.
[7] J Pons and J Dunlop, “Enhanced system level/link level simulation interface for GSM”, Vehicular Technology Conference, 1999. VTC 1999 - Fall. IEEE VTS 50th, pp 1189 – 1193.
[8] Carlo Caini, Guido Riva, “A New Vector Quantization Technique for Performance Evaluation in Frequency Hopping Mobile Radio Systems”, IEEE COMMUNICATIONS LETTERS, VOL. 4, NO. 8, AUGUST 2000, pp 252 – 254.
[9] GSM 03.03, “Radio Network Planning Aspects”, ETSI, 1996.
[10] GSM 05.05, “Radio Transmission and Reception”, ETSI, 1993.
[11] Martin Keller, “A comprehensive simulation approach to study FH in two GSM system regarding the physical layer level and the system level”, Vehicular Technology Conference, 1997, IEEE 47th, pp 1852 – 1856.