Journal articles: 'Wideband Code Division Multiple Access (WCDMA)'

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Kavipriya, P., and C. Gomathi. "OVSF Code Assignment for Wideband Code Division Multiple Access (WCDMA) in FPGA." i-manager’s Journal on Wireless Communication Networks 1, no. 3 (December 15, 2012): 8–13. http://dx.doi.org/10.26634/jwcn.1.3.2049.

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D, Sivaganesan. "IMPROVISATION OF MESH NETWORK WITH WIDEBAND CODE DIVISION MULTIPLE ACCESS." IRO Journal on Sustainable Wireless Systems 01, no. 03 (September 28, 2019): 198–205. http://dx.doi.org/10.36548/jsws.2019.3.006.

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Mesh Networks are employed in various applications despite issues relevant to interference and network capacity. These networks also impose delay in routing and reconfiguration. Traditionally, TDMA and FDMA techniques have been used in these networks. This paper proposes wideband code division multiple access (WCDMA) technique for enabling maximum power transfer, low energy consumption, interference free and plug-and-play feature enabling easy implementation of the technology. The spatial configuration and node count bounds are stated ensuring continuous satisfaction of quality of service by the communication link. Additionally, dynamic parallel orthogonal transmission and turbo coding schemes are used in combination to improve the efficiency of the network even for large hop counts.

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Ariyanti, Sri. "Studi Penentuan Spesifikasi Teknis Terminal Wideband Code Division Multiple Access (WCDMA)." Buletin Pos dan Telekomunikasi 12, no. 2 (March 20, 2015): 135. http://dx.doi.org/10.17933/bpostel.2014.120205.

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SHARMA, Sanjay Kumar, and S. Naseem AHMAD. "BER Performance of Space-Time Coded MMSE DFE for Wideband Code Division Multiple Access (WCDMA)." International Journal of Communications, Network and System Sciences 02, no. 04 (2009): 276–82. http://dx.doi.org/10.4236/ijcns.2009.24030.

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Surya Winata, I. Gusti Ngurah, Gede Sukadarmika, and Pande Ketut Sudiarta. "ANALISIS DROP CALL PADA JARINGAN WIDEBAND CODE-DIVISION MULTIPLE ACCESS (WCDMA) DI CLUSTER RENON." Jurnal SPEKTRUM 6, no. 1 (May 9, 2019): 44. http://dx.doi.org/10.24843/spektrum.2019.v06.i01.p07.

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Drop call is an example of a problem that is often experienced by users of voice telecommunications services. From this condition, this riset raises the topic of drop call analysis on WCDMA networks in the Renon cluster (nodeB MYAMIN_CR, AKABA_PL, and BUNDARANRENON_PL). Data retrieval needed (Call Set Up Success Rate (CSSR), Call Drop Ratio (CDR), RSCP and Ec/No) is done by drive test using G-NetTrack Pro software. Based on the analysis of the results of the drive test, there were 10 drop call problems. The problems indentified cause by missing neighbors, handover failure, bad spot, coverage problems and overshoot. Bad spots, coverage problems, and overshoot are the initial causes of missing neighbors and handovers failure. Missing neighbors and handover failure begins with the poor value of RSCP and Ec/No, so that the cellphone will try to do a handover. To analyze the drive test results, drive test data is carried out using Atoll software. From the comparison found extreme conditions resulting from obstacle which cause a significant difference in value between the results of the drive test and simulation. The high attenuation rate drop call location due to the obstacle also results in RSCP and Ec/No values being obtained when measurements in the field are low. The low parameter values of RSCP and Ec / No then cause a drop call.

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Li, Jin Zheng, Wei Xia, Zi Shu He, De Jun Zeng, and Xiao Wei Kong. "A Parallelizable Adaptive Method to Update Close-Loop Digital Predistorter for RF Power Amplifiers." Applied Mechanics and Materials 130-134 (October 2011): 4252–55. http://dx.doi.org/10.4028/www.scientific.net/amm.130-134.4252.

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This paper presents a parallelizable adaptive method to estimate and update close-loop digital predistorter for RF power amplifiers. The proposed scheme can be realized with multiple processors which can save computational time and be used in real-time implementation. By using a three-carrier wideband code-division multiple access (WCDMA) signal, the scheme is tested in the way of 3 branches in Nios II. Results show that the performance is approximate to that based on RLS algorithm and the time the scheme expensed is much less than that RLS needed.

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Lee, Hongmin, and Jinwon Park. "Isolation Improvement of a Microstrip Patch Array Antenna for WCDMA Indoor Repeater Applications." International Journal of Antennas and Propagation 2012 (2012): 1–8. http://dx.doi.org/10.1155/2012/264618.

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This paper presents the isolation improvement techniques of a microstrip patch array antenna for the indoor wideband code division multiple access (WCDMA) repeater applications. One approach is to construct the single-feed switchable feed network structure with an MS/NRI coupled-line coupler in order to reduce the mutual coupling level between antennas. Another approach is to insert the soft surface unit cells near the edges of the microstrip patch elements in order to reduce backward radiation waves. In order to further improve the isolation level, the server antenna and donor antenna are installedinorthogonal direction. The fabricated antenna exhibits a gain over 7 dBi and higher isolation level between server and donor antennas below −70 dB at WCDMA band.

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Eli-Chukwu, N. C., and G. N. Onoh. "Experimental Study on the Impact of Weather Conditions on Wide Code Division Multiple Access Signals in Nigeria." Engineering, Technology & Applied Science Research 9, no. 2 (April 10, 2019): 3998–4001. http://dx.doi.org/10.48084/etasr.2630.

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In cellular network activities, before a site is integrated it is expected that each cell of the site meets the Nigerian Communication Commission (NCC) standard of ≥98% for both service accessibility and call completion rate which in turn depicts a ≤2% in both blocked call rate (BCR) and dropped call rate (DCR). It is suggested that weather conditions have a very strong negative effect on the performance of wideband code division multiple access (WCDMA) network as it could lead to signal attenuation or change the polarization. In this paper, we study the impact of weather conditions on WCDMA network in Nigeria. To achieve this, network samples (log-files) were collected weekly during a driving test in Enugu State Nigeria for a period of five years for both rainy and dry seasons, in which blocked and dropped calls were extracted. Results show that during adverse weather conditions, BCR and DCR rise greater than 8% and 4% respectively. Although with a slight relationship between the weather conditions, the weather condition during the dry season has a better-blocked call rate of 8.76% in comparison with the rainy season with 12.89%. Calls tend to drop more during the dry season. From the outcome of the experiment, a model was developed for predicting an unknown network call statistics variables.

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Crespo-Cadenas, Carlos, Javier Reina-Tosina, and María J. Madero-Ayora. "Performance of a behavioral model with long-term memory effects." International Journal of Microwave and Wireless Technologies 5, no. 4 (April 23, 2013): 447–52. http://dx.doi.org/10.1017/s1759078713000408.

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This paper presents a new behavioral model for power amplifiers that accomplishes the capture of nonlinear low-frequency memory effects with reduced complexity and superior precision. It has been extensively evaluated with a commercial amplifier using wideband code-division multiple-access (WCDMA)-like modulated data with symbol rates in the range of 2 ksym/s to 1 Msym/s, and it is shown that the first dynamic reduction of the proposed model is successfully compared with other highly efficient methods in terms of complexity and generalization capacity.

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Grekhov, Andrii, Vasyl Kondratiuk, and Svitlana Ilnytska. "RPAS COMMUNICATION CHANNELS BASED ON WCDMA 3GPP STANDARD." Aviation 24, no. 1 (May 11, 2020): 42–49. http://dx.doi.org/10.3846/aviation.2020.12166.

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First built models of Remotely Piloted Air System (RPAS) communication channels based on Wideband Code Division Multiple Access (WCDMA) 3GPP Standard were designed. Base Station (BS) transmission within the Radio Line of Sight (RLoS) and through the satellite using Beyond Radio Line of Sight (BRLoS) was considered. The dependencies of the Bit Error Rate (BER) on the signal-noise ratio for different RPAS velocities and WCDMA сhannel models were obtained. The dependences of the BER on the signal-noise ratio for different levels of satellite transponder nonlinearity were studied. The dependence of the BER on the BS antenna diameter in case of the transponder nonlinearity was analysed. The dependencies for satellite channel characteristics, first obtained taking into account the motion of the RPAS, make it possible to predict the behavior of the communication system in critical conditions.

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Shirvani-Moghaddam, Shahriar, and Hajar Sadeghi. "A New Combination of RAKE Receiver and Adaptive Antenna Array Beamformer for Multiuser Detection in WCDMA Systems." International Journal of Antennas and Propagation 2011 (2011): 1–9. http://dx.doi.org/10.1155/2011/208301.

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The aim of this paper is to combine smart antenna beamforming and RAKE receiver in wideband code division multiple access (WCDMA). The proposed method combines spatial diversity as well as temporal diversity to improve the performance and overcome both interferences and multipath fading. This investigation has focused on one of the new proposed blind beamforming algorithms. It is based on constrained constant modulus (CCM) algorithm which is used for deriving a recursive-least-squares (RLS-) type optimization algorithm. We illustrate the comparison of bit error rate (BER) of the proposed receiver with simple correlator and also 1D-RAKE receiver in multiuser detection (MUD) WCDMA. The simulation results show that the proposed 2D-RAKE receiver offers lower BER rather than conventional ones, that is, it is an effective solution for decreasing the effect of interference and increasing the capacity, in a joint state.

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Suresh, T., and K. L. Shunmuganathan. "Efficient Resource Sharing Architecture for Multistandard Communication System." VLSI Design 2011 (May 24, 2011): 1–9. http://dx.doi.org/10.1155/2011/328640.

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The Fourth Generation (4G) network is expected to serve mobile subscribers under dynamic network conditions and offer any type service: anytime, anywhere, and anyhow. Two such technologies that can respond to the above said services are Wideband Code Division Multiple Access (WCDMA) and Orthogonal Frequency Division Multiplexing (OFDM). The main contribution of this paper is to propose a dedicated hardware module which can reconfigure itself either to the OFDM Wireless LAN or WCDMA standard. In this paper, Fast Fourier Transform (FFT) algorithm is implemented for OFDM standard, and rake receiver is implemented for WCDMA standard. Initially efficient implementations of these two algorithms are tested separately and identified the resources utilized by them. Then the new hardware architecture, which configures to any one of these two standards on demand, is proposed. This architecture efficiently shares the resources needed for these two standards. The proposed architecture is simulated using ModelSimSE v6.5 and mapped onto a virtex 5 FPGA device (xc5v1x30ff324) using the tool Xilinx ISE 9.2i, and the results are compared with the standard approach. These results show that the proposed hardware architecture utilizes less number of resources compared to the conventional Reconfigurable Receiver Architecture System.

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Wentzel, Andreas, Shinichi Hori, Makoto Hayakawa, Kazuaki Kunihiro, and Wolfgang Heinrich. "Digital PA with voltage-mode topology using envelope delta-sigma modulation." International Journal of Microwave and Wireless Technologies 5, no. 3 (June 2013): 285–92. http://dx.doi.org/10.1017/s1759078713000457.

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This paper reports on digital transmitter architecture for the 450 MHz band using an envelope delta-sigma modulator realized in CMOS and a voltage-mode class-S (VMCS) power amplifier (PA) based on GaN monolithic microwave integrated circuits (MMICs). The class-S PA is characterized for narrowband single-tone signals and a single- as well as a four-carrier downlink wideband code division multiple access (WCDMA) signal with a peak-to-average power ratio of 7.5 dB. Using single-tone excitation the PA shows a maximum drain efficiency of 86% and a peak output power of 4.4 W. At 6 and 10 dB back-off, 59 and 36% efficiency are achieved, respectively. With the single- and four-carrier WCDMA input signals maximum drain efficiencies of 64 and 53% are reached, respectively, and peak output power is 0.7 W. The adjacent channel leakage ratio shows values of about −34 dBc (5 MHz) and −38 dBc (10 MHz) for single-carrier WCDMA excitation. This is the first complete VMCS PA chain characterized with standard communication signals.

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Rullyanto, Rullyanto, and Mohamad Fathoni. "Analisa Unjuk Kerja Sistem Downlink Dedicated Channel (DCH) Pada Wideband CDMA." Jurnal Ilmiah Giga 16, no. 1 (July 8, 2019): 17. http://dx.doi.org/10.47313/jig.v16i1.586.

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Sistem seluler Wideband Code Division Multiple Acces (WCDMA) saat ini berkembang sangat pesat pada tugas akhir ini dilakukan Analisa Unjuk Kerja Sistim Downlink Dedicated Channel (DCH) pada Wideband CDMA. Untuk menganalisa performa atau unjuk kerja dari sistem Downlink DCH pada Wideband CDMA dicari nilai kesalahan bit pada saat pengiriman yang biasa dikenal dengan nama Bit Error Rate pada Cyclic Redundancy Check (CRC) dan channel coding dengan input Dedicated Traffik Channel (DTCH) dan Dedicated Control Channel (DCCH) dicari nilai Bit Error Rate (BER) pada sistem Downlink Dedicated Channel (DCH) Wideband CDMA dan dicari nilai Block Error Rate (BLER) pada sistem Downlink Dedicated Channel (DCH) Wideband CDMA. Analisa ini menggunakan piranti lunak Matlab 7.0.1 untuk mengetahui jumlah kesalahan Bit Error Rate (BER) dengan jenis kanal Multipath Fading. Dari hasil simulasi dengan Input 106 pada 7 dB dengan menggunakan Eb/No dari 1 hingga 7 dB maka didap atkan Bit Error Rate dengan nilai Bit Error Rate BER 1,8 x 10^-6.

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Jovanovic, Borisav, and Srdjan Milenkovic. "The peak windowing for PAPR reduction in software defined radio base stations." Facta universitatis - series: Electronics and Energetics 33, no. 2 (2020): 273–87. http://dx.doi.org/10.2298/fuee2002273j.

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The utilization of the techniques for Peak to Average Power Ratio (PAPR) reduction makes the wireless infrastructure conform to rigorous telecommunication standard specifications (error vector magnitude (EVM), bit error rate (BER), transmit spectrum mask (TSM)). In modern modulation schemes reduction of PAPR is important requirement for distortion free and energy-efficient operation of power amplifiers (PA). In this paper novel implementation of Peak Windowing method for PAPR reduction in Software Defined Radio (SDR) Base Stations (BS) is presented. The measurement results in terms of EVM and ACPR are given for 5 MHz, 10 MHz, 15 MHz, 20 MHz Long-Term Evolution (LTE) and Wideband Code Division Multiple Access (WCDMA) modulations. In case of 10MHz LTE signal, we achieved PAPR = 8 dB, EVM = 2.0%, ACPR -52dBc at modulated PA output, antenna point.

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Lallet, Julien, Sébastien Pillement, and Olivier Sentieys. "Efficient and Flexible Dynamic Reconfiguration for Multi Context Architectures." Journal of Integrated Circuits and Systems 4, no. 1 (November 21, 2009): 36–44. http://dx.doi.org/10.29292/jics.v4i1.295.

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Dynamic reconfiguration is possible on both fine-grain and coarse-grain architectures. One of the used methodology used consists in the use of multi-context architectures. Unfortunately, the multiple contexts bring power and area overhead. This paper introduces the Dynamic Unifier and reConfigurable blocK (DUCK) concept, a new structure to perform efficiently dynamic reconfiguration on both custom designed fine-grain and coarse grain architectures. The DUCK allows to separate the configuration path and the configuration registers which facilitates simultaneous configuration and computing steps. The reconfiguration process is presented in detail, and synthesis results are given for different structures. Our solution is finally validated with the implementation of a WCDMA (Wideband Code Division Multiple Access) receiver on a multi-context embedded FPGA and on the dynamically reconfigurable processor DART. This implementation demonstrates the interest and the efficiency of the use of dynamic reconfiguration and the proposed flexible structure.

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Fauzi, Achmad, and Widya Cahyadi. "DESAIN DAN IMPLEMENTASI ANTENA HELIX DAN RECTANGULAR PATCH DENGAN INSET FEED UNTUK PASSIVE REPEATER PADA FREKUENSI WCDMA." Transmisi 22, no. 2 (June 30, 2020): 38–44. http://dx.doi.org/10.14710/transmisi.22.2.38-44.

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Penguatan sinyal pada indoor building dapat membantu mempermudah proses transmisi data yang menggunakan jaringan Wideband Code Division Multiple Access (WCDMA). Penguatan di dalam bangunan perlu dilakukan meskipun lokasi Base Transceiver Station (BTS) cukup dekat karena terjadinya pelemahan yang disebabkan oleh tebal tembok maupun faktor-faktor lainnya. Salah satu solusi yang dapat ditawarkan adalah dengan perancangan repeater pasif dengan menggunakan antena dalam ruang berupa helix dan rectangular patch sebagai antena luar ruang. Antena helix dan rectangular patch diimplementasikan dan disambungkan dengan kabel koaksial RG58 sebagai saluran transmisi. Pengaplikasian repeater pasif dilakukan di bangunan rumah yang memiliki jarak kurang lebih 130 meter dari BTS namun memiliki kualitas sinyal yang buruk karena tembok beton yang tebal dan banyaknya pepohonan. Data diambil dengan melihat hasil sebelum dan sesudah diterapkannya repeater pasif dengan penambahan jarak antara handout dengan antenna indoor mulai dari 0 cm hingga 5 cm dengan peningkatan maksimal sebesar 8 dB.

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Dong, Jian, Xiaping Yu, and Guoqiang Hu. "Design of a Compact Quad-Band Slot Antenna for Integrated Mobile Devices." International Journal of Antennas and Propagation 2016 (2016): 1–9. http://dx.doi.org/10.1155/2016/3717681.

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In order to incorporate different communication standards into a single device, a compact quad-band slot antenna is proposed in this paper. The proposed antenna is composed of a dielectric substrate, T-shaped microstrip patch with a circle slot and an inverted L-slot, and a comb-shaped ground on the back of the substrate. By adopting these structures, it can produce four different bands, while maintaining a small size and a simple structure. Furthermore, a prototype of the quad-band antenna is designed and fabricated. The simulated and measured results show that the proposed antenna can operate over the 1.79–2.63 GHz, 3.46–3.97 GHz, 4.92–5.85 GHz, and 7.87–8.40 GHz, which can cover entire PCS (Personal Communications Service, 1.85–1.99 GHz), UMTS (Universal Mobile Telecommunications System, 1.92–2.17 GHz), WCDMA (wideband code-division multiple access, 2.1 GHz), Bluetooth (2.4–2.48 GHz), WiBro (Wireless Broad band access service, 2.3–3.39 GHz), WLAN (Wireless Local Area Networks, 2.4/5.2/5.8 GHz), WiMAX (Worldwide Interoperability for Microwave Access, 2.5/3.5/5.5 GHz), and X-band SATcom applications (7.9~8.4 GHz). The proposed antenna is particularly attractive for mobile devices integrating multiple communication systems.

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Gkonis, P., D. Kaklamani, I. Venieris, C. Dervos, M. Chrysomallis, K. Siakavara, and G. Kyriakou. "On the Reduction of Transmission Complexity in MIMO-WCDMA Frequency-Selective Fading Orientations via Eigenvalue Analysis." Electronics 7, no. 10 (October 5, 2018): 239. http://dx.doi.org/10.3390/electronics7100239.

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In this paper, a novel transmission strategy for Mutliple Input Multiple Output Wideband Code Division Multiple Access (MIMO-WCDMA) orientations operating in frequency-selective fading environments is investigated, in terms of overall algorithmic complexity reduction. To this end, Principal Component Analysis (PCA) is employed on the received data matrix, in order to define the significant terms that are taken into account during transmission matrix formulation. According to the presented results, feedback information of only the primary eigenvector of the corresponding covariance matrix of the received data matrix is required, in order to maintain the mean Bit Error Rate (BER) at acceptable levels. In particular, a complexity reduction of up to 10% can be achieved, when comparing BER values derived by the selection of all components of the received covariance matrix during transmission matrix formulation, and the corresponding BER when selecting half of the components. This reduction is maintained to 10%, when considering a realistic four-element antenna design; however, in this case mean BER inaccuracy is further reduced to 1%.

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Diet, Antoine M., Nicolas Ribière-Tharaud, Martine Villegas, and Geneviève Baudoin. "Front-end HPA/antenna for multi-radio." International Journal of Microwave and Wireless Technologies 4, no. 5 (May 1, 2012): 483–93. http://dx.doi.org/10.1017/s1759078712000372.

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This paper focuses on multi-radio front-end transmitter, a function implied by cognitive radio (0.5–6 GHz). S and C bands standards (wireless local and metropolitan area networks) present a challenge, due to the signal modulation schemes (orthogonal frequency division multiplex (OFDM)/WCDMA, wideband code division multiple access) dynamic (tens of dBs), driving us to a mandatory transmitter linearization. The idea is to provide frequency, flexibility, and average power control of a multi-radio high-efficiency front end for such signals (polar/envelope elimination and restoration (EER) structure). The study implies antennas design and average power control demonstration. Based on a switched mode power amplifier (PA), a discrete detuning is possible to adapt the PA at both “WiMAX” and “Wifi5” frequencies. This architecture amplifies signals with amplitude information. This is coded here by the ΣΔ/PWM (pulse width modulation) technique, to present a constant envelope signal. The amplitude information is restored by a pass-band radio frequency (RF) filter. The antenna can be designed with a notch, to reduce the filtering constraints (selectivity and standards coexistences) and to help in the restoration of amplitude information. Average power control is illustrated by voltage supply variation and results are a possible dynamic of 9.5 dB. To complete the analysis, the simulation of the propagation channel, including antennas, with CST (free space, line of sight) is imported under AGILENT-ADS.

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Mahardhika, Gita, Mahamod Ismail, and Rosdiadee Nordin. "Vertical Handover Decision Algorithm Using Multicriteria Metrics in Heterogeneous Wireless Network." Journal of Computer Networks and Communications 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/539750.

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Heterogeneous network concept was introduced to satisfy the demands of network’s traffic capacity and data rate. It consists of multiplatform networks with various radio access technologies. Conventionally, a mobile user may roam and accomplish the vertical handover using single criteria, such as received signal strength (RSS). Single criteria vertical handover decision, however, may cause inefficient handoff, unbalanced network load, and service interruption. This paper proposed an improved vertical handover decision using multicriteria metrics in the environment of heterogeneous network consisting of three network interfaces: (i) wireless local area network (WLAN), (ii) wideband code division multiple access (WCDMA), and (iii) worldwide interoperability for microwave access (WiMAX). In the vertical handover decision, four metrics are considered: (i) RSS, (ii) mobile speed, (iii) traffic class, and (iv) network occupancy. There are three types of the vertical handover decision algorithm: (i) equal priority, (ii) mobile priority, and (iii) network priority. Equal priority multicriteria handover algorithm improved the number of handoffs by 46.60 while mobile priority multicriteria algorithm improved the number of handoffs by 90.41% and improved the balance index by 0.09%. Network priority multicriteria method improved the number of handoffs by 84.60%, balance index by 18.03%, and average blocking probability by 20.23%.

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Nakatani, Toshifumi, Donald F. Kimball, Lawrence E. Larson, and Peter M. Asbeck. "0.7–1.8 GHz multiband digital polar transmitter using watt-class current-mode class-D CMOS power amplifier and digital envelope modulation technique for reduced spurious emissions." International Journal of Microwave and Wireless Technologies 5, no. 3 (April 23, 2013): 271–84. http://dx.doi.org/10.1017/s175907871300041x.

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A polar transmitter driven by digital input signals for envelope and phase is demonstrated, using a band-switching output resonator to achieve multiband operation. A new digital pulse width modulation algorithm is also shown to partially suppress spurious signals associated with the digital input envelope signal. The transmitter consists of a current-mode class-D (CMCD) CMOS power amplifier (PA), together with a buck converter with a dead-time generator for improved efficiency. The CMCD PA is tuned by band-switching capacitors that can handle up to 9 V, and is measured to have approximately 30 dBm output power with 31–35% drain efficiency under single-tone testing. The proposed spurious signal reduction technique works to partially suppress quantization noise without increasing power consumption. Overall efficiencies of 27.1/25.6% are obtained at 30.2/28.9 dBm continuous wave (CW) output powers and 0.85/1.75 GHz carrier frequencies, respectively. Spur suppression of 9–10 dB peak is achieved when the proposed algorithm is applied with wideband code division multiple access (WCDMA) modulation.

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Ahmadi, Kayvan, Massoud Dousti, and Shahrooz Asadi. "A Highly Extended High-Efficiency Range Class-F–C Doherty Power Amplifier." Journal of Circuits, Systems and Computers 29, no. 09 (December 19, 2019): 2050152. http://dx.doi.org/10.1142/s0218126620501522.

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This paper presents a new extended high-efficiency-range Doherty power amplifier (DPA) with a main and only a single auxiliary amplifier. In order to extend the output high-efficiency range with a high-efficiency level, asymmetrical cells are employed as the main and auxiliary amplifiers in class-F and class-C complex combining load (CCL) methodology, respectively. To verify the proposed methodology, a DPA with 12-dB output back-off (OBO) is designed and fabricated for wideband code division multiple access (WCDMA) applications. Large-signal continuous-wave measurement results show the power gain of about 11[Formula: see text]dB with a drain efficiency of 59.9% at 12[Formula: see text]dB of OBO. A two-tone test exhibits a third-order intermodulation distortion (IMD) of lower than [Formula: see text][Formula: see text]dBc. Modulated wave measurements show over 55% of average drain efficiency and an adjacent channel leakage power ratio (ACLR) of lower than [Formula: see text][Formula: see text]dBc at an output power level of 31.5[Formula: see text]dBm.

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Hühn, Florian, Andreas Wentzel, and Wolfgang Heinrich. "A new modulator for digital RF power amplifiers utilizing a wavetable approach." International Journal of Microwave and Wireless Technologies 9, no. 6 (July 2017): 1251–60. http://dx.doi.org/10.1017/s1759078717000770.

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This paper presents for the first time a wavetable-based coding scheme to generate a high-speed binary input signal for digital RF power amplifiers. The approach maximizes the utilization of the time domain handling capabilities of the pulse forming circuit. Key features are a greatly improved output spectrum purity in comparison with common digital modulators, the ability to adjust the modulator to any given pulse forming hardware and a built-in signal correction option that comes without additional computational cost. To give a first impression on the modulators behavior and its possibilities to adapt to different hardware constraints, simulations are carried out for different parameter variations and for different baseband bandwidths. Furthermore, the proposed concept is emulated with an arbitrary waveform generator to gather additional measurement data. For a 5 MHz wideband code division multiple access (WCDMA) signal (6.5 dB peak-to-average power ratio) at 900 MHz, an error vector magnitude (EVM) of 0.26% and better than >58 dB adjacent channel leakage ratio (ACLR) were recorded. To the authors’ knowledge, these are the best values achieved so far for a single-bit coding scheme without digital predistortion that still maintains maximum power coding efficiency.

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Kim, Sung Do, Jong So Kim, Byeong Min Mun, and Suk Joo Bae. "A Bayesian Virtual Metrology for Quality Inspection of Mobile Repeater Systems." Management and Production Engineering Review 7, no. 4 (December 1, 2016): 48–53. http://dx.doi.org/10.1515/mper-2016-0035.

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Abstract The technology of wideband code division multiple access (WCDMA) has been applied to band selective interference cancellation system (ICS) repeaters. To inspect the telecommunication quality of the systems, quality engineers must check the shape of the signals at the corresponding frequency band of the repeaters. However, measuring the signal quality is a repetitive manual task which requires much inspection time and high costs. In the case of small-sized samples, such as the example of an ICS repeater system, Bayesian approaches have been employed to improve the estimation accuracy by incorporating prior information on the parameters of the model in consideration. This research proposes a virtual method of quality inspection for products using a correlation structure of measurement data, mainly in a Bayesian regression framework. The Bayesian regression model derives prior information from historical measurement data to predict measurements of other frequency bandwidths by exploiting the correlation structure of each measurement data. Empirical results show the potential for reducing inspection costs and time by predicting the values of adjoining frequency bandwidths through measured data of a frequency bandwidth in the course of quality inspections of ICS repeater systems.

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Monther Yousif, Siba, Roslina M. Sidek, Anwer Sabah Mekki, Nasri Sulaiman, and Pooria Varahram. "Efficient Low-Complexity Digital Predistortion for Power Amplifier Linearization." International Journal of Electrical and Computer Engineering (IJECE) 6, no. 3 (June 1, 2016): 1096. http://dx.doi.org/10.11591/ijece.v6i3.10328.

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<span lang="EN-US">In this paper, a low-complexity model is proposed for linearizing power amplifiers with memory effects using the digital predistortion (DPD) technique. In the proposed model, the linear, low-order nonlinear and high-order nonlinear memory effects are computed separately to provide flexibility in controlling the model parameters so that both high performance and low model complexity can be achieved. The performance of the proposed model is assessed based on experimental measurements of a commercial class AB power amplifier by applying a single-carrier wideband code division multiple access (WCDMA) signal. The linearity performance and the model complexity of the proposed model are compared with the memory polynomial (MP) model and the DPD with single-feedback model. The experimental results show that the proposed model outperforms the latter model by 5 dB in terms of adjacent channel leakage power ratio (ACLR) with comparable complexity. Compared to MP model, the proposed model shows improved ACLR performance by 10.8 dB with a reduction in the complexity by 17% in terms of number of floating-point operations (FLOPs) and 18% in terms of number of model coefficients.</span>

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Monther Yousif, Siba, Roslina M. Sidek, Anwer Sabah Mekki, Nasri Sulaiman, and Pooria Varahram. "Efficient Low-Complexity Digital Predistortion for Power Amplifier Linearization." International Journal of Electrical and Computer Engineering (IJECE) 6, no. 3 (June 1, 2016): 1096. http://dx.doi.org/10.11591/ijece.v6i3.pp1096-1105.

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<span lang="EN-US">In this paper, a low-complexity model is proposed for linearizing power amplifiers with memory effects using the digital predistortion (DPD) technique. In the proposed model, the linear, low-order nonlinear and high-order nonlinear memory effects are computed separately to provide flexibility in controlling the model parameters so that both high performance and low model complexity can be achieved. The performance of the proposed model is assessed based on experimental measurements of a commercial class AB power amplifier by applying a single-carrier wideband code division multiple access (WCDMA) signal. The linearity performance and the model complexity of the proposed model are compared with the memory polynomial (MP) model and the DPD with single-feedback model. The experimental results show that the proposed model outperforms the latter model by 5 dB in terms of adjacent channel leakage power ratio (ACLR) with comparable complexity. Compared to MP model, the proposed model shows improved ACLR performance by 10.8 dB with a reduction in the complexity by 17% in terms of number of floating-point operations (FLOPs) and 18% in terms of number of model coefficients.</span>

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Abdulkawi, Wazie M., Waqar Ahmad Malik, Sajjad Ur Rehman, Abdul Aziz, Abdel Fattah A. Sheta, and Majeed A. Alkanhal. "Design of a Compact Dual-Band MIMO Antenna System with High-Diversity Gain Performance in Both Frequency Bands." Micromachines 12, no. 4 (April 1, 2021): 383. http://dx.doi.org/10.3390/mi12040383.

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A compact four-element dual-band multiple-input and multiple-output (MIMO) antenna system is proposed to achieve high isolation and low channel capacity loss. The MIMO antenna was designed and optimized to cover the dual-frequency bands; the first frequency band is a wide band, and it covers the frequency range of 1550–2650 MHz, while the other frequency band covers the 3350–3650 MHz range. The measured wide-band impedance bandwidths of 1.1 GHz and 300 MHz were achieved in the lower and upper frequency bands, respectively. The proposed structure consists of four novel antenna elements, along with a plus-sign-shaped ground structure on an FR4 substrate. The overall electrical size of the whole dual-band MIMO antenna system is 0.3λ(W) × 0.3λ(L) × 0.008λ(H) for the lower frequency band. It achieved greater than 10 and 19 dB isolation in the lower and upper frequency bands, respectively. The antenna system accomplished an envelope correlation coefficient of |ρ|≤0.08 in the lower frequency band, while it achieved |ρ|≤0.02 in the higher frequency band. The computed channel capacity loss remained less than almost 0.4 bits/s/Hz in both frequency bands. Therefore, it achieved good performance in both frequency bands, with the additional advantage of a compact size. The proposed MIMO antenna is suitable for compact handheld devices and smartphones used for GSM (Global System for Mobiles), UMTS (Universal Mobile Telecommunications Service), WCDMA (Wideband Code Division Multiple Access), LTE (Long Term Evolution), 5G sub-6 GHz, PCS (Personal Communications Service), and WLAN (wireless local area network) applications.

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Milstein, L. B. "Wideband code division multiple access." IEEE Journal on Selected Areas in Communications 18, no. 8 (August 2000): 1344–54. http://dx.doi.org/10.1109/49.864000.

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Adelakun, A. O., B. Y. Lawal, M. A. Adekoya, and K. E. Ukhurebo. "Chaotic assessment of the key performance indicators for a GSM Network congestion in an election period in Nigeria." Nigeria Journal of Pure and Applied Physics 9, no. 1 (April 21, 2020): 28–33. http://dx.doi.org/10.4314/njpap.v9i1.6.

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This paper investigates the chaos-based assessment of the Key performance Indicators (KPIs) for the Cellular network congestion during and after 2011 People Democratic Party (PDP) presidential primary election in Eagle Square within Abuja and its environs. Chaotic quantifiers such as average mutual information, Lyapunov exponents and specific attenuation were employed to study the congestion rate or dynamical state of the network. The chaotic assessment of the Wideband Code Division Multiplexing Access (WCDMA) data services provided by MTN network using KPIs are reported. The data retrieved from the three Base Transceiver Stations (BTSs) were used to analyse the performance of the network. The results revealed the state of dynamical behaviour of the congestion during the study period. Keywords: Key performance Indicators (KPIs); Wideband Code Division Multiplexing Access (WCDMA); Global System of Mobile communication (GSM); Base Transceiver Station (BTS); Chaotic Quantifiers

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Yang, Zong-kai, Guang-ran Liu, and Jian-hua He. "New code match strategy for wideband code division multiple access code tree management." Journal of Central South University of Technology 13, no. 3 (June 2006): 265–69. http://dx.doi.org/10.1007/s11771-006-0121-6.

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Chukwudebe, Gloria A., Emmanuel N. Ekwonwune, and Florence O. Elei. "Quality of Service (QoS) Evaluation in Wideband Code Division Multiplexing Access (WCDMA) Networks Using Empirical Analysis Methods." Communications and Network 12, no. 02 (2020): 61–73. http://dx.doi.org/10.4236/cn.2020.122004.

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W, Herdianna Kusuma. "Comparison Simulator Data Rate Modulation QPSK and 16 QAM System WCDMA (Wide Code Division Multiple Access) and HSDPA (High Speed Downlink Packet Access)." Jurnal Jartel: Jurnal Jaringan Telekomunikasi 1, no. 1 (March 30, 2015): 34–42. http://dx.doi.org/10.33795/jartel.v1i1.130.

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HSDPA (High Speed Downlink Packet Access) is the upgrade performance data packets extraordinary against WCDMA thus producing top speed 14,4 Mbps. One of the goals the creation of HSDPA is as an improvement over previous technologies. The expected improvement of HSDPA technology increasing the data rate is capable of exceeding data rate in order to WCDMA customer satisfaction in accessing multimedia content such as streaming video and data at high speed. Data Rate is the maximum data rate that can be accepted by the UE (User Equipment) in ideal conditions. One of the factors that affect the data rate is modulation scheme used by each of the technologies. QPSK modulation is used in WCDMA system and adaptive modulation (QPSK and 16QAM) is used in HSDPA system.In the research the results obtained by selection of symbol rate of 480 kbps bit rate will yield 960 kbps while the selection symbol rate is 960 kbps will produce 1920 kbps bit rate using modulation QPSK modulation. As for 16QAM modulation, symbol rate of 480 kbps produces 1920 kbps and symbol rate is 960 kbps bit rate produces 3840 kbps. Of the trial results, the more number of bits sent then the higher data rate that can be accepted by the UE (user equipment).

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Adiyansyah Indra, Win, Saravanan A/L Sukumaran, Khalil Azha Mohd Annuar, and Irianto . "Analysis of Handover Planning in Wideband Code Division Multiple Access (W–CDMA)." Journal of Engineering and Applied Sciences 14, no. 3 (December 20, 2019): 823–30. http://dx.doi.org/10.36478/jeasci.2019.823.830.

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Alani, Omar Younis. "Adaptive multi-component service model for Wideband Code Division Multiple Access systems." International Journal of Mobile Communications 6, no. 6 (2008): 667. http://dx.doi.org/10.1504/ijmc.2008.019818.

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Hameed, A., and Ali Oudah. "Interference in Wireless Networks: Causes, Analyses and Practical Mitigating Techniques." Modern Applied Science 8, no. 5 (August 5, 2014): 56. http://dx.doi.org/10.5539/mas.v8n5p56.

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This paper addresses the key characteristics of interference in wireless networks. Moreover, it considers the impact of interference from Code Division Multiple Access base station to Wideband-Code Division Multiple Access one. A detailed discussion of major interference mitigation techniques in wireless networks, in general, and CDMA and W-CDMA systems, in particular is also imparted on. The techniques and findings in this paper can be easily used in the analyses of other wireless technologies.

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Saini, Davinder, Ankit Gupta, and Aditi Joshi. "Reducing code wastage in orthogonal variable spreading factor-based wideband code division multiple access networks." International Journal of Communication Systems 26, no. 7 (November 17, 2011): 863–74. http://dx.doi.org/10.1002/dac.1374.

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Al-nahari, A. Y., S. A. El-Dolil, M. I. Dessouky, and F. E. Abd El-Samie. "Reservation-based dynamic admission control scheme for wideband code division multiple access systems." Journal of Central South University 19, no. 2 (January 28, 2012): 393–401. http://dx.doi.org/10.1007/s11771-012-1017-2.

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Liu, Huaping. "Interference and Queuing Delay Based Uplink Packet Access Control in Wideband Code-Division Multiple-Access Systems." International Journal of Wireless Information Networks 10, no. 3 (July 2003): 141–47. http://dx.doi.org/10.1023/b:ijwi.0000007995.41492.64.

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Norio. "A Fuzzy Logic Based Power Control for Wideband Code Division Multiple Access Wireless Networks." Journal of Computer Science 8, no. 8 (August 1, 2012): 1372–79. http://dx.doi.org/10.3844/jcssp.2012.1372.1379.

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Nasreddine, J., O. Sallent, J. Pérez-Romero, and R. Agustí. "Advanced spectrum management in wideband code division multiple access systems enabling cognitive radio usage." IET Communications 2, no. 6 (2008): 794. http://dx.doi.org/10.1049/iet-com:20070497.

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Paul, Rajarshi, Luke Sankey, Luca Corradini, Zoya Popovic, and Dragan Maksimovic. "Power Management of Wideband Code Division Multiple Access RF Power Amplifiers With Antenna Mismatch." IEEE Transactions on Power Electronics 25, no. 4 (April 2010): 981–91. http://dx.doi.org/10.1109/tpel.2009.2036355.

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Purnomowati, Ir Endah Budi, Gaguk Asmungi, and Anindito Yusuf Wirawan. "Pathloss Calculation and Analysis Using Different Carrier Frequency on Wideband Code Division Multiple Access Technology." Advanced Science Letters 21, no. 10 (October 1, 2015): 3185–88. http://dx.doi.org/10.1166/asl.2015.6436.

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Lee, J. H., A. B. Raju, and R. M. Buehrer. "Characterisation of wideband code division multiple access uplink transmit power for typical mobile usage patterns." IET Microwaves, Antennas & Propagation 5, no. 5 (2011): 535. http://dx.doi.org/10.1049/iet-map.2010.0101.

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Saini, Davinder, and Neeru Sharma. "Reduction in code blocking using scattered vacant codes for orthogonal variable spreading factor-based wideband code division multiple access networks." IET Communications 7, no. 1 (January 4, 2013): 40–48. http://dx.doi.org/10.1049/iet-com.2011.0715.

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Balyan, Vipin, and Davinder S. Saini. "Same rate and pattern recognition search of orthogonal variable spreading factor code tree for wideband code division multiple access networks." IET Communications 8, no. 13 (September 5, 2014): 2366–74. http://dx.doi.org/10.1049/iet-com.2013.0814.

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Baghersalimi, Gholamreza, and Timothy O'Farrell. "Pilot-aided estimation and equalisation of a Radio-over-Fibre system in Wideband Code Division Multiple Access." IET Communications 7, no. 10 (July 2, 2013): 999–1007. http://dx.doi.org/10.1049/iet-com.2012.0660.

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Zhao, L., and J. W. Mark. "Joint rate and power adaptation for radio resource management in uplink wideband code division multiple access systems." IET Communications 2, no. 4 (2008): 562. http://dx.doi.org/10.1049/iet-com:20060336.

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Ahmed, B. T., and M. C. Ramón. "Downlink capacity and interference statistics of wideband code division multiple access microcells for trains in long tunnels." IET Communications 3, no. 4 (2009): 603. http://dx.doi.org/10.1049/iet-com.2008.0356.

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Lee, Jeong-An, Seung-Bok Byun, Jong-Hyuk Lim, and Tae-Yeoul Yun. "Reconfigurable antenna for wideband code division multiple access and Korean satellite digital multimedia broadcasting controlled by pin-diodes." Microwave and Optical Technology Letters 49, no. 6 (2007): 1334–37. http://dx.doi.org/10.1002/mop.22413.

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Journal articles on the topic 'Wideband Code Division Multiple Access (WCDMA)'

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