Results 221 to 230 of about 5,642,826 (267)

Hash Division Multiple Access

2016 IEEE Global Communications Conference (GLOBECOM), 2016
Recent advances in rateless codes facilitate the utilization of dense constellation. By exploiting more constellation points with controlled symbol distance, they ensure higher transmission date rate and better diversity gain against fading. In this paper, we observe that there exists certain redundancy in the existing dense constellation diagram. With
Lu Wang 0002, Xiaoke Qi, Kaishun Wu, Qian Zhang 0001   +3 more
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Index Modulation Multiple Access

2018 IEEE 29th Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), 2018
In this paper, the use of index modulation (IM) technique for non-orthogonal multiple access (NOMA) is presented, called the Index Modulation multiple access (IMMA). From the concept of index modulation, IMMA technique uses the active subcarriers and inactive subcarriers to make index indices.
Yung-Ta Lai, Yi-Ruei Ciou, Jen-Ming Wu
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A hybrid access method in a multiple access channel

Performance Evaluation, 1986
Abstract 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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A multiple access for unlicensed spectrum

2012 IEEE International Symposium on Circuits and Systems, 2012
The 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, Rendong Ying, Xu Wang, Fan He, Bo Hu 0002   +4 more
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On the capacity of multiplicative multiple access channels with AWGN

2011 IEEE Information Theory Workshop, 2011
We consider a multiplicative multiple access channel in the presence of additive white Gaussian noise. Under individual average power constraints at each of the transmitters, we characterize the capacity region of this channel. The structure of the region reveals some fundamental characteristics related to timesharing, power constraints and the ...
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Sparse code multiple access

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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On interleave-division multiple-access

2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577), 2004
This work provides a comprehensive study of IDMA systems. We first outline the basic IDMA principles in single-path and multi-path environments. We then describe a simple semi-analytical technique to assess the performance of IDMA systems, based on which we develop a power allocation scheme for performance optimization.
Li Ping 0001, Lihai Liu, Keying Wu, Raymond W. K. Leung   +3 more
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Multiple access modulation techniques

Communications Satellite Systems Conference, 1966
Abstract 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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Sparse index multiple access

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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On multiple access channels with feedback

IEEE Trans. Inf. Theory, 1984
Summary: For the binary erasure multiple access channel, \textit{E. C. van der Meulen} [ibid. IT-23, 1-37 (1977; Zbl 0355.94035)] showed in his survey paper that the symmetrical rate pair (0.79113, 0.79113) is achievable in the case of feedback. Here we prove that this rate point is on the boundary of the feedback capacity region. Subsequently we apply
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