Frequency overlay of GSM and cellular B-CDMA

Koorevaar, P.; Ruprecht, J.

doi:10.1109/isssta.1996.563177

Cited by 5 publications

(8 citation statements)

References 7 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: 61%

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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: 61%

“…F, has been derived in [7], and is based on the difference in GSM camer frequencies in adjacent cells:…”

Section: Inter-cell Gsm Inte#erence To Cdma Ngsmlmentioning

confidence: 99%

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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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“…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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“…Naturally, code-division multiple access (CDMA) is the usual platform for such overlay, due to its multiple accessing capabilities and immunity to narrowband interference (NBI) [1], [2]. Simulation results in [3] showed that net system capacity can be considerably increased when a wideband CDMA (W-CDMA) system is laid upon the global system for mobile communications (GSM) network, which was further justified experimentally in [4] and [5]. The legacy GSM signal acts as a NBI to the wideband CDMA; the suppression of such signals (i.e., tone jammers or digitally modulated signals) has been well studied, see the excellent overview in [7] and references therein.…”

Section: Introductionmentioning

confidence: 99%

Parallel Interference Cancellation for Uplink Multirate Overlay CDMA Channels

Yan

Roy

2005

IEEE Trans. Commun.

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Abstract-To provide new and/or higher rate wireless services with limited spectrum resources, frequency overlay has been naturally proposed to accommodate the new and legacy systems in a common band. In this paper, we address the multiuser detection problem for overlaid code-division multiple-access (CDMA) scenarios. However, in contrast to the well-studied conventional single-rate CDMA, miscellaneous systems overlay almost always indicates the presence of multirate traffic that introduces an additional degree of freedom in receiver design-i.e., differences in the symbol rates. In this paper, we concentrate on receiver design for multirate traffic, while assuming a lack of information exchange between the constituent (new and legacy) systems, as is commonplace in practice. We propose a receiver architecture based on linear parallel interference cancellation where the out-of-rate intersystem interference is estimated and subtracted by means of its characteristic subspace, thereby avoiding the need for the exact knowledge of signature waveforms of the interfering system. Simulation results validate our solution and show that the proposed receiver has better performance in various aspects than several other solutions for the same purpose. IndexTerms-Code-division multiple-access (CDMA), group-blind detection, multirate processing, parallel interference cancellation (PIC), spectral overlay.

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Frequency overlay of GSM and cellular B-CDMA

Cited by 5 publications

References 7 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

Theoretical Investigation into Spectral Coexistence of CDMA and TDMA Systems

Parallel Interference Cancellation for Uplink Multirate Overlay CDMA Channels

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