Analysis and results for the orthogonality factor in WCDMA downlinks

Mehta, Neelesh B.; Greenstein, L.J.; Willis, T.M.; Kostic, Z.

doi:10.1109/vtc.2002.1002672

Cited by 25 publications

(25 citation statements)

References 8 publications

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“…In this section we present a new link/system level interface. It is based on a simplified description of intracell interference, called orthogonality factor [1][2][3], which we discuss first.…”

Section: A Orthogonality Factormentioning

confidence: 99%

“…We point out difficulties in applying common approaches such as average value interface and actual value interface [4], which offer simple singlevalued parameterizations of link-level simulations but cannot deal well with new link adaptation and radio resource management techniques used in HSDPA. Further analysis leads us to proposing a new link/system interface based on the concept of orthogonality factor (OF) [1][2][3]. Our method provides an efficient way of modeling frequency-selective fading on a system level and Rake receiver on a link level, which we regard as the key issue in modeling of HDSPA system.…”

mentioning

confidence: 99%

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Variable orthogonality factor: a simple interface between link and system level simulation for high speed downlink packet access

Seeger¹,

Sikora

Klein

2003

2003 IEEE 58th Vehicular Technology Conference. VTC 2003-Fall (IEEE Cat. No.03CH37484)

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Detailed simulations of the full physical layer operation of a cellular network are usually performed in two stages, link level and system level. Emergence of new link adaptation and radio resource management techniques together with need for higher modeling accuracy are blurring the line separating these stages. In this paper we address the issue of performing a link level/system level separation and defining the interface between them for simulating High Speed Downlink Packet Access (HSDPA), a part of WCDMA standard. The main challenge is to model frequency selective fading on the system level, while retaining the Rake receiver on the link level. We present available strategies and propose a novel interface based on variable orthogonality factor (OF), which serves as a compact description of the momentary channel impulse response. Finally, we present HSDPA simulation results demonstrating the high accuracy of our approach.

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Section: A Orthogonality Factormentioning

confidence: 99%

mentioning

confidence: 99%

Variable orthogonality factor: a simple interface between link and system level simulation for high speed downlink packet access

Seeger¹,

Sikora

Klein

2003

2003 IEEE 58th Vehicular Technology Conference. VTC 2003-Fall (IEEE Cat. No.03CH37484)

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“…Although the spreading sequences used in CDMA are designed to show orthogonality between them when perfect synchronism is achieved, multipath channels introduce Multiple Access Interference due to the loss of orthogonality of the time-shifted versions of the spreading sequences. This effect is usually modelled in analysis and simulations by means of the time averaged value of the orthogonality factor.1 Some authors, [1,2], have recently worked in a complete characterization of this parameter.…”

Section: Introductionmentioning

confidence: 99%

Spreading Sequence Assignment in WCDMA for Distributed Antenna Arrays Based on Interference Model

Botella

Piñero

González

et al. 2006

2006 IEEE 7th Workshop on Signal Processing Advances in Wireless Communications

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A new spreading sequence assignment scheme for WCDMA is proposed in this paper. It is based on a simple but exhaustive model of the interferences involved: Multiple Access (MAI) and InterFinger Interferences (IFI) at a mobile RAKE receiver output. These interferences are mainly determined in this work by the correlation properties of the spreading sequences. The new approach assigns spreading sequences in a way that minimum interference power between active users can be achieved. Simulation results show that the new scheme outperforms natural (consecutive ordering) scheme for the typical central situation of antenna arrays in a cell, but these benefits are even higher for a configuration of distributed antenna arrays around the cell.

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“…where SF 16 denotes spreading factor 16 as used for the HS-DSCH, P Rx,DSCH is the received desired HS-DSCH signal power, P own is the received own cell interference, P other is the received other cell interference, and α is the so-called downlink orthogonality factor [11]- [12]. Note that (6) is derived under the assumption that a standard single antenna Rake receiver is used at the new user.…”

Section: Quality Based Hsdpa Access Algorithmmentioning

confidence: 99%

“…Assuming a priori knowledge of α, ρ can be estimated by the RNC according to (11), since the rest of the terms are known via measurements from the Node-B and the user. Given the estimated average HS-DSCH SINR at the new user, the average throughput that the user can be served with equals f (ρ) for the special case where the user is scheduled in every TTI with all the available HSDPA transmission power.…”

Section: Quality Based Hsdpa Access Algorithmmentioning

confidence: 99%

Quality based HSDPA access algorithms

Pedersen¹

VTC-2005-Fall. 2005 IEEE 62nd Vehicular Technology Conference, 2005.

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A new quality based HSDPA access algorithm is derived, which only admits new users provided that the specified QoS requirements can be fulfilled. The proposed algorithm is designed so that it takes both priority and minimum bit rate requirements into account in the decision process. As a case study, the quality based HSDPA access algorithm is tested by means of dynamic network simulations with streaming traffic on HSDPA. For a maximum allowable unsatisfied user probability of 5% it is found that the proposed algorithm results in up to 30% cell capacity gain, as compared to not having admission control.

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Analysis and results for the orthogonality factor in WCDMA downlinks

Cited by 25 publications

References 8 publications

Variable orthogonality factor: a simple interface between link and system level simulation for high speed downlink packet access

Variable orthogonality factor: a simple interface between link and system level simulation for high speed downlink packet access

Spreading Sequence Assignment in WCDMA for Distributed Antenna Arrays Based on Interference Model

Quality based HSDPA access algorithms

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