Modified Optimum Beamforming for Smart Antenna in WCDMA Network

Singla, Parveen; Saxena, Jyoti

doi:10.1109/icmira.2013.37

Cited by 6 publications

(4 citation statements)

References 22 publications

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“…Simulation results revealed that MUSIC is the more effective option to use for high velocity sources and poor channel conditions, same results as reported by Vesa [79], Sawada et al [80], and Singla and Saxena [81].…”

Section: Beamforming-based Schemessupporting

confidence: 84%

Doppler Shift Compensation Schemes in VANETs

Nyongesa¹,

Djouani²,

Olwal³

et al. 2015

Mobile Information Systems

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Over the last decade vehicle-to-vehicle (V2V) communication has received a lot of attention as it is a crucial issue in intravehicle communication as well as in Intelligent Transportation System (ITS). In ITS the focus is placed on integration of communication between mobile and fixed infrastructure to execute road safety as well as nonsafety information dissemination. The safety application such as emergence alerts lays emphasis on low-latency packet delivery rate (PDR), whereas multimedia and infotainment call for high data rates at low bit error rate (BER). The nonsafety information includes multimedia streaming for traffic information and infotainment applications such as playing audio content, utilizing navigation for driving, and accessing Internet. A lot of vehicular ad hoc network (VANET) research has focused on specific areas including channel multiplexing, antenna diversity, and Doppler shift compensation schemes in an attempt to optimize BER performance. Despite this effort few surveys have been conducted to highlight the state-of-the-art collection on Doppler shift compensation schemes. Driven by this cause we survey some of the recent research activities in Doppler shift compensation schemes and highlight challenges and solutions as a stock-taking exercise. Moreover, we present open issues to be further investigated in order to address the challenges of Doppler shift in VANETs.

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Section: Beamforming-based Schemessupporting

confidence: 84%

Doppler Shift Compensation Schemes in VANETs

Nyongesa¹,

Djouani²,

Olwal³

et al. 2015

Mobile Information Systems

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“…Singla [14] proposed a data-dependent criteria to improve the MVDR weight. This method used constraints function instead of a single linear equality constraint.…”

Section: Related Workmentioning

confidence: 99%

Modifying MVDR Beamformer for Reducing Direction-of-Arrival Estimation Mismatch

Abdulrahman

Rahman

Hassnawi³

et al. 2015

Arab J Sci Eng

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The minimum variance distortionless response (MVDR) beamforming algorithm is used in smart antenna design for wireless communication. The operation of MVDR is based on finding the optimum weight to direct the main lobe beam to the desired user location with a unity gain. MVDR is very sensitive to signature vector mismatch. This mismatch occurs due to waveform deformation, local scattering, imperfect array element calibration and element shape distortion, which leads to errors in finding the direction of arrival (DOA) of the signal. In this paper, a new technique to modify the MVDR is presented, modelled and evaluated. The proposed algorithm is named modified MVDR (MMVDR) and is dependent on reconstructing the signature vector (steering vector) and the covariance matrix to introduce accurate beamformer weight by re-localization the reference element to be in the middle of ULA, rather than at one end side. The new reference position partitions the array's elements into two groups around this reference, which leads to treat received signals with identical phase along the array's elements, as well as increasing the degree of freedom to deals with different types of uniform arrays. The evaluation results show that MMVDR outperforms MVDR with respect to beamformer accuracy, system cost, processing time and signal classification to overcome the errors in DOA estimation which occur due to fabrication and calibration errors.

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“…In general, any uplink signal from the MS can be used to estimate the AoA, but typically a known signal such as the Sounding Reference Signals (SRSs) or DeModulation Reference Signals (DM-RS) would be used [12]. In order to construct the shape of the downlink beam, direction of arrival estimation already exists and is supported in WCDMA but it is not standardized [13]. According to the angle of arrival, the cell is divided into ranges like in figure 2 relative to the angle between the UE, the BS and the geographical north.…”

Section: A Network Used Metricsmentioning

confidence: 99%