The capacity of broadband CDMA overlaying a GSM cellular system

Grieco, D.; Schilling, D. L.

doi:10.1109/vetec.1994.345170

Cited by 20 publications

(7 citation statements)

References 3 publications

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“…This number is not common for spreading codes, however, that is of little relevance to this study as our aim is to make a fair comparison. Although, some effects have still been disregarded, such as the distributions of modeled errors and fading, we believe to have quantified the effects of the following system and implementation aspects to the capacity of co-existent GSM and CDMA: Without imperfections and with moderate shadowing, ow results match those seen in recent literature [4,7], i.e., a capacity increase factor between 3 and 4. In an imperfection scenario with shadowing, the capacity improvement due to the overlay could reduce to less than 60%.…”

Section: Discussionsupporting

confidence: 59%

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Capacity of co-existent cellular CDMA and GSM with shadowing and imperfect sectorization, power control and notch filtering

Moelker

Prasad²

Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97

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Overlay of existing narrowband mobile communication systems with future wideband systems may improve spectrum efficiency and create the possibility for high-rate data services. This paper presents a generic capacity analysis applied to a GSM-CDMA overlay. The effects of shadowing and imperfect implementation of sectorization, power control and notch filtering are modeled for both uplink and downlink. Based on maximum allowable levels of mutual interference, the total system capacity is modeled and evaluated.Under moderate shadowing and perfect implementation of sectorization, power control and notch filtering, the results match those obtained in previous analyses by other authors, i.e., a capacity gain factor between 3 and 4. However, for low GSM margins in addition to imperfect sectorization, power control and notch filtering, the capacity gain is shown to reduce significantly. Particularly under heavy shadowing conditions, the overlay does not lead to capacity gain. The propagation loss factor and notch filtering are shown to have a large influence on the results. Provided almost perfect notch filtering and power control, the downlink performs slightly better than the uplink.

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Section: Discussionsupporting

confidence: 59%

“…Several studies have shown the potential for a significant capacity increase, i.e., a factor 3 to 4, e.g. [4,7].…”

Section: Introductionmentioning

confidence: 99%

Capacity of co-existent cellular CDMA and GSM with shadowing and imperfect sectorization, power control and notch filtering

Moelker

Prasad²

Proceedings of 8th International Symposium on Personal, Indoor and Mobile Radio Communications - PIMRC '97

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“…Known solutions of macrocellular COMA overlay consist in narrowband notch filters in the transmitters and receivers of overlay. The characteristics of notch filters used in a given sector of overlay must be chosen adequatly to attenuate frequencies utilised in that sector by GSM system [5][6][7]. This approach can also be used in the picocellular overlay considered, however, only in such a case when a picocell is located somewhere in the middle of a sector of GSM system's macrocell (see Fig.…”

Section: Cdma Overlaymentioning

confidence: 99%

“…In general, by CDMA overlay we understand a mobile communication system based on DS-CDMA technique that is sharing frequency band with another mobile communication system based on TDMA or FDMA technique. In the literature one can find many publications in this topics [5][6][7][8][9]. However, only macro cellular overlay, covering fully the area of GSM cells, has been considered so far.…”

Section: Introductionmentioning

confidence: 99%

A Picocellular CDMA/TDD Overlay on GSM

Kaczorek

Rutkowski

2000

Personal Wireless Communications

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To improve the utilisation of frequency bands assigned to GSM system, an idea of CDMA overlay seems to be interesting. In this paper a picoceUular CDMAfIDD overlay on GSM system has been considered. It is corresponding to a TDD mode ofWCDMA proposed by ETSI, ARIB and TIA for the future third generation UMTSlIMT2000 system. The overlay is proposed for indoor operation in the area of macrocell of GSM system. As it turns out the implementation of overlay can significantly increase the spectrum efficiency in the frequency band that is shared by GSM system and the overlay. The picocellular CDMAfIDD overlay can be used both for speech and data transmission.

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“…The need for future multiple access schemes employing an overlay is stressed in many papers (Schilling, Lomp and Garodnick, 1993;Grieco and Schilling, 1994;Himimy and Gupta, 1996;Widdowson, 1997;Koorevaar and Ruprecht, 1999). In all these papers simulation algorithms were used to study the effects of overlaying different schemes on the performance of the hybrid systems.…”

Section: Introductionmentioning

confidence: 99%

Theoretical Investigation into Spectral Coexistence of CDMA and TDMA Systems

Abbosh

Shehathah

2008

Jou. Eng. Res.

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The scarcity of available radio spectrum presently limits the extension of modern multimedia systems. This paper presents a theoretical investigation into the possibility of using a frequency overlay of a narrowband Code Division Multiple Access (CDMA) System and a Time Division Multiple Access (TDMA) System to provide a greater spectral efficiency. This paper shows that under certain conditions the two systems can operate in the same frequency band and in the same area with a considerable improvement in the overall capacity of the whole system.

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The capacity of broadband CDMA overlaying a GSM cellular system

Cited by 20 publications

References 3 publications

Capacity of co-existent cellular CDMA and GSM with shadowing and imperfect sectorization, power control and notch filtering

Capacity of co-existent cellular CDMA and GSM with shadowing and imperfect sectorization, power control and notch filtering

A Picocellular CDMA/TDD Overlay on GSM

Theoretical Investigation into Spectral Coexistence of CDMA and TDMA Systems

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