Results 171 to 180 of about 36,530 (229)
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IEEE Communications Magazine, 1997
The authors present an overview of new multiple access schemes based on a combination of code division and multicarrier techniques, such as multicarrier code-division multiple access (MC-CDMA), multicarrier direct sequence CDMA (multicarrier DS-CDMA), and multitone CDMA (MT-CDMA).
Shinsuke Hara, Ramjee Prasad
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The authors present an overview of new multiple access schemes based on a combination of code division and multicarrier techniques, such as multicarrier code-division multiple access (MC-CDMA), multicarrier direct sequence CDMA (multicarrier DS-CDMA), and multitone CDMA (MT-CDMA).
Shinsuke Hara, Ramjee Prasad
exaly +2 more sources
Proceedings of the Sixth IEEE Computer Society Workshop on Future Trends of Distributed Computing Systems, 2002
This paper shows how reliable data services can be provided in an error prone wireless environment using CDMA and a link layer retransmission protocol. A CDMA encoder using Walsh codes for 1.85 to 1.99 GHz PCS applications is simulated under various error conditions with varying packet size to determine minimum acceptable QOS relative to error ...
David Cypher, Shukri Wakid
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This paper shows how reliable data services can be provided in an error prone wireless environment using CDMA and a link layer retransmission protocol. A CDMA encoder using Walsh codes for 1.85 to 1.99 GHz PCS applications is simulated under various error conditions with varying packet size to determine minimum acceptable QOS relative to error ...
David Cypher, Shukri Wakid
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Gated-CDMA: Frequency-Domain Equalization for CDMA Systems
IEICE Transactions on Communications, 2005While CDMA systems are proven to be excellent solutions for cellular communications, they suffer from severe multi-path interferences and are hard to support high-data-rate transmissions over frequency-selective fading channels. This letter introduces a novel downlink transmission method for next generation mobile communication systems.
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Performance Analysis of DS-CDMA and MC-CDMA Systems
2018 9th IEEE Annual Ubiquitous Computing, Electronics & Mobile Communication Conference (UEMCON), 2018In this paper, a performance analysis of DS-CDMA and MC-CDMA is conducted. With DS-CDMA, data is spread using a spreading sequence in the time domain. In contrast, with MC-CDMA, data is spread over different sub-carriers using a spreading sequence in the frequency domain. The comparison of DS-CDMA and MC-CDMA is presented under an AWGN channel.
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IEEE Global Telecommunications Conference, 2004. GLOBECOM '04., 2005
Our topic is channel equalizer quantization for a cellular handset. We answer questions regarding quantization of variables internal to the equalizer using some estimated bounds and simulation. This includes the catastrophic event of breakdown due to a roundoff-induced singularity in Cholesky factorization.
Thomas A. Sexton +5 more
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Our topic is channel equalizer quantization for a cellular handset. We answer questions regarding quantization of variables internal to the equalizer using some estimated bounds and simulation. This includes the catastrophic event of breakdown due to a roundoff-induced singularity in Cholesky factorization.
Thomas A. Sexton +5 more
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IEEE Journal on Selected Areas in Communications, 1995
A method for optical signaling is investigated that allows multiple transmitters to simultaneously use the same noncoherent receiving aperture. The signaling is based on the properties of laser speckle interference patterns. Capacity for an interference limited system is explored for a correlation receiver based on random coding.
Hassan, Amer A. +2 more
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A method for optical signaling is investigated that allows multiple transmitters to simultaneously use the same noncoherent receiving aperture. The signaling is based on the properties of laser speckle interference patterns. Capacity for an interference limited system is explored for a correlation receiver based on random coding.
Hassan, Amer A. +2 more
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Convolutional Spreading CDMA and Comparison With the DS-CDMA With RAKE Receiver
IEEE Transactions on Communications, 2006For synchronous downlink direct-sequence code-division multiple access (DS-CDMA), we introduce a cyclic-prefix (CP)-based convolutional spreading CDMA (CS-CDMA/CP) scheme employing zero correlation zone (ZCZ) codes, which gives a class of multiuser interference (MUI)-free CDMA schemes, including Suehiro's CDMA and block spreading (BS) CDMA as special ...
Nalin S. Weerasinghe, Takeshi Hashimoto
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Spectral overlay of multicarrier CDMA on existing CDMA mobile systems
IEEE Communications Letters, 1999A spectral overlay of a narrow-band code division multiple access (CDMA) system and a wide-band multicarrier CDMA system is considered as a means for existing CDMA mobile networks to evolve into a future CDMA network. The achievable joint capacity of the overlaid system is provided and compared with that of another network evolution strategy of ...
Il Gyu Kim, Dongwoo Kim 0001
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On Asymptotic Efficiency for Asynchronous CDMA
2007 41st Annual Conference on Information Sciences and Systems, 2007We consider asynchronous CDMA systems and analyze their performances in terms of asymptotic efficiency when linear receivers are employed and the system becomes overloaded. We show that in such systems, differently from synchronous systems, linear detectors can be asymptotically efficient and, specifically, that the MMSE detector is asymptotically ...
ROMANO, Gianmarco +3 more
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Frequency coordination between CDMA and non-CDMA systems
Proceedings of 1995 IEEE MTT-S International Topical Symposium on Technologies for Wireless Applications (Conjunction with INTER COMM'95), 2002Mutual interference between non-CDMA (FM and TDMA) subscriber stations (SS) and CDMA base stations (BS), as well as interference between CDMA SS and non-CDMA BS are investigated. The noise figure is used as a measure of degradation of the receiver performance.
S. Soliman, C. Wheatley
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