Results 251 to 260 of about 8,202,004 (293)
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A multiple access for unlicensed spectrum
2012 IEEE International Symposium on Circuits and Systems, 2012The current multiple accesses, such as CDMA, are designed for multi-user wireless communication systems in the licensed spectrum, where uncoordinated interferences can be kept to a minimum. On the other hand, the uncoordinated interferences do exist in the unlicensed spectrum, and they compromise the orthogonal properties and hence degrade the ...
Ruey-Wen Liu +4 more
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On Simple Multiple Access Networks
IEEE Journal on Selected Areas in Communications, 2015We investigate a simple multiple access network (SMAN) where $k$ independent sources of unit rates multicast their information to a set of sinks, via $n$ commonly shared relays. All links are assumed to have unit capacity. Given such a SMAN, a coding scheme for the relays is called optimal if each sink can retrieve all information from the ...
Son Hoang Dau, Wentu Song, Chau Yuen
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A hybrid access method in a multiple access channel
Performance Evaluation, 1986Abstract This paper considers a multiple-access communication channel with an infinite number of users. We show that if a controlled slotted Aloha protocol is used, then messages with variable length will have a negative impact on the average message delay.
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2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 2013
Multicarrier CDMA is a multiplexing approach in which modulated QAM symbols are spread over multiple OFDMA tones by using a generally complex spreading sequence. Effectively, a QAM symbol is repeated over multiple tones. Low density signature (LDS) is a version of CDMA with low density spreading sequence allowing us to take advantage of a near optimal ...
Hosein Nikopour, Hadi Baligh
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Multicarrier CDMA is a multiplexing approach in which modulated QAM symbols are spread over multiple OFDMA tones by using a generally complex spreading sequence. Effectively, a QAM symbol is repeated over multiple tones. Low density signature (LDS) is a version of CDMA with low density spreading sequence allowing us to take advantage of a near optimal ...
Hosein Nikopour, Hadi Baligh
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The Interference-Multiple-Access Channel
2009 IEEE International Conference on Communications, 2009We introduce the interference-multiple-access channel, which is a discrete memoryless channel with two transmitters and two receivers, similar to the interference channel. One receiver is required to decode the information encoded at one transmitter, the other receiver is required to decode the messages from both transmitters. We provide an inner bound
Etienne Perron +2 more
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Satellite multiple access protocols
IEEE Communications Magazine, 1980This paper presents a tutorial on the varioupsr otocols used in satellite data transmission. The most important characteristic of the satellite system is the ability of the earth stations, located at geographically dispersed areas, to access the satellite to transmit and to receive data.
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Cognitive multiple access networks
Proceedings. International Symposium on Information Theory, 2005. ISIT 2005., 2005A cognitive radio can sense the transmission of other users in its environment and possibly extract the corresponding messages. It can use this information to transmit over the same channel while reducing interference from, and to other users. In this paper, we define inter/intra-cluster competitive, cooperative, and cognitive behavior in wireless ...
Natasha Devroye +2 more
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Multiple access modulation techniques
Communications Satellite Systems Conference, 1966Abstract This paper quantitatively and qualitatively compares the following multiple-access satellite communication techniques: frequency-division multiple access (FDMA), time-division multiple access (TDMA), spread-spectrum multiple access (SSMA), and pulse-address multiple access (PAMA).
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Proceedings of the November 12-14, 1963, fall joint computer conference on XX - AFIPS '63 (Fall), 1963
During the past two years disc files have been accepted as a reliable and economic form of mass random-access memory. It is now possible to design disc file systems which are functionally and logically optimized to provide efficient operation for a wide range of applications.
Irving L. Wieselman +2 more
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During the past two years disc files have been accepted as a reliable and economic form of mass random-access memory. It is now possible to design disc file systems which are functionally and logically optimized to provide efficient operation for a wide range of applications.
Irving L. Wieselman +2 more
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2015 IEEE Global Conference on Signal and Information Processing (GlobalSIP), 2015
In this paper, we consider sparse index modulation (SIM) for precoded orthogonal frequency division multiplexing (OFDM) and its generalization to multi-carrier multiple access systems. The resulting multiple access is called sparse index multiple access (SIMA).
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In this paper, we consider sparse index modulation (SIM) for precoded orthogonal frequency division multiplexing (OFDM) and its generalization to multi-carrier multiple access systems. The resulting multiple access is called sparse index multiple access (SIMA).
openaire +1 more source