Mode Modulation for Wireless Communications With a Twist
28 Aug 2018-IEEE Transactions on Vehicular Technology (Institute of Electrical and Electronics Engineers (IEEE))-Vol. 67, Iss: 11, pp 10704-10714
TL;DR: Numerical results demonstrate that the mode modulation (MM) based OAM system can offer a new mode dimension for vorticose communications and the AMM scheme can achieve larger SE than the EMM scheme.
Abstract: Recently, orbital angular momentum (OAM) based vorticose communication has attracted much attention because of its potential to significantly increase the spectrum efficiency (SE) of wireless communications. However, the multiple radio frequency (RF) chains used for multiple OAM modes lead to an unexpected cost for wireless vorticose communications. In this paper, we first propose the mode modulation (MM) based OAM system to allow multiple OAM modes sharing a common RF chain. The proposed MM cannot only reduce the hardware cost, but also boost the SE by introducing the mode as an additional dimension for data transmission. Moreover, without the channel state information (CSI) feedback, we develop an equal-probability mode modulation (EMM) scheme to maximize the SE of MM-based OAM systems with the limited RF chains. In addition, with the CSI feedback, we develop a Huffman coding based adaptive mode modulation (AMM) scheme, which can adaptively choose the OAM modes to further increase the SEs of OAM-based wireless communications. We also develop the joint power and probability allocation policy for the AMM scheme to achieve the maximum SEs for OAM-based vorticose communications. Numerical results demonstrate that the MM can offer a new mode dimension for vorticose communications and the AMM scheme can achieve larger SE than the EMM scheme.
Citations
More filters
TL;DR: In this paper, a comprehensive discussion of 6G is given based on the review of 5G developments, covering visions and requirements, technology trends and challenges, aiming at tackling the challenge of coverage, capacity, the user data rate and movement speed of mobile communication system.
Abstract: Since 5G new radio comes with non-standalone (NSA) and standalone (SA) versions in 3GPP, research on 6G has been on schedule by academics and industries. Though 6G is supposed to have much higher capabilities than 5G, yet there is no clear description about what 6G is. In this article, a comprehensive discussion of 6G is given based on the review of 5G developments, covering visions and requirements, technology trends and challenges, aiming at tackling the challenge of coverage, capacity, the user data rate and movement speed of mobile communication system. The vision of 6G is to fully support the development of a Ubiquitous Intelligent Mobile Society with intelligent life and industries. Finally, the roadmap of the 6G standard is suggested for the future.
292 citations
Posted Content•
TL;DR: A comprehensive discussion of 6G is given based on the review of 5G developments, covering visions and requirements, technology trends and challenges, aiming at tackling the challenge of coverage, capacity, the user data rate and movement speed of mobile communication system.
Abstract: Since 5G new radio comes with non-standalone (NSA) and standalone (SA) versions in 3GPP, research on 6G has been on schedule by academics and industries. Though 6G is supposed to have much higher capabilities than 5G, yet there is no clear description about what 6G is. In this article, a comprehensive discussion of 6G is given based on the review of 5G developments, covering visions and requirements, technology trends and challenges, aiming at tackling the challenge of coverage, capacity, the user data rate and movement speed of mobile communication system. The vision of 6G is to fully support the development of a Ubiquitous Intelligent Mobile Society with intelligent life and industries. Finally, the roadmap of the 6G standard is suggested for the future.
200 citations
TL;DR: The mathematical derivation shows that the proposed TOO MIMO system based on a simple switching sequence is suitable for small-scale and low-cost wireless broadband communications, and the simulation results demonstrate that the TOOMIMO scheme achieves a considerable SE and much less computational complexity than the OFDM-OAM MIMo scheme.
Abstract: Orbital angular momentum (OAM) has attracted considerable attention as a novel solution for wireless communications because its orthogonal modes significantly increase the channel capacity without an additional frequency band. The joint multiplexing between OAM technologies and other modulation techniques has not been thoroughly investigated. In this paper, we first proposed the orthogonal frequency-division multiplexing-orbital angular momentum (OFDM-OAM) multiple-input-multiple-output (MIMO) system. The proposed OFDM-OAM MIMO based on the discrete Fourier transformation (DFT) operations achieves a very high sum-rate and spectrum efficiency (SE). However, the expensive hardware and software overheads for transmitting and receiving OAM waves lead to an unexpected cost for the OFDM-OAM MIMO scheme. A time-switched OFDM-OAM (TOO) MIMO is then proposed to reduce the computational complexity, and the procedure of OAM generations and recoveries has also explicitly been derived. The mathematical derivation shows that the proposed TOO MIMO system based on a simple switching sequence is suitable for small-scale and low-cost wireless broadband communications, and the simulation results demonstrate that the TOO MIMO scheme achieves a considerable SE and much less computational complexity than the OFDM-OAM MIMO scheme.
32 citations
Cites methods from "Mode Modulation for Wireless Commun..."
...Besides, an adaptive mode modulation (AMM) scheme with Huffman coding was proposed in [32] to improve significantly the SE of the OAM-based communication systems....
[...]
TL;DR: The future issues and challenges to be faced by the 6G technology are discussed from every aspect from hardware to the enabling technologies which will be utilized by 6G.
Abstract: In 2030, we are going to evidence the 6G mobile communication technology, which will enable the Internet of Everything. Yet 5G has to be experienced by people worldwide and B5G has to be developed; the researchers have already started planning, visioning, and gathering requirements of the 6G. Moreover, many countries have already initiated the research on 6G. 6G promises connecting every smart device to the Internet from smartphone to intelligent vehicles. 6G will provide sophisticated and high QoS such as holographic communication, augmented reality/virtual reality and many more. Also, it will focus on Quality of Experience (QoE) to provide rich experiences from 6G technology. Notably, it is very important to vision the issues and challenges of 6G technology, otherwise, promises may not be delivered on time. The requirements of 6G poses new challenges to the research community. To achieve desired parameters of 6G, researchers are exploring various alternatives. Hence, there are diverse research challenges to envision, from devices to softwarization. Therefore, in this article, we discuss the future issues and challenges to be faced by the 6G technology. We have discussed issues and challenges from every aspect from hardware to the enabling technologies which will be utilized by 6G.
32 citations
Cites background from "Mode Modulation for Wireless Commun..."
...OAM modes are topological charges....
[...]
...Reflection and refraction of OAM waves changes the wave-front of OAM modes and makes the signal transmissions difficult during fading scenarios....
[...]
...It gives the opportunity for multiplexing/demultiplexing the OAM modes together which enhances the capacity of the signal....
[...]
...Orbital angular momentum (OAM) [24] is a new resource for modulation in the 6G network....
[...]
...However, OAM modulation has many issues such as beam divergence, transmission and transceiver misalignment....
[...]
TL;DR: Analysis of the crucial requirements to develop 6G network infrastructure is presented and a list of important networking and communication technologies that shall indeed play the vital role to design 6G is presented.
25 citations
References
More filters
Book•
03 Mar 1993
TL;DR: The book is a solid reference for professionals as well as a useful text for students in the fields of operations research, management science, industrial engineering, applied mathematics, and also in engineering disciplines that deal with analytical optimization techniques.
Abstract: COMPREHENSIVE COVERAGE OF NONLINEAR PROGRAMMING THEORY AND ALGORITHMS, THOROUGHLY REVISED AND EXPANDED"Nonlinear Programming: Theory and Algorithms"--now in an extensively updated Third Edition--addresses the problem of optimizing an objective function in the presence of equality and inequality constraints. Many realistic problems cannot be adequately represented as a linear program owing to the nature of the nonlinearity of the objective function and/or the nonlinearity of any constraints. The "Third Edition" begins with a general introduction to nonlinear programming with illustrative examples and guidelines for model construction.Concentration on the three major parts of nonlinear programming is provided: Convex analysis with discussion of topological properties of convex sets, separation and support of convex sets, polyhedral sets, extreme points and extreme directions of polyhedral sets, and linear programmingOptimality conditions and duality with coverage of the nature, interpretation, and value of the classical Fritz John (FJ) and the Karush-Kuhn-Tucker (KKT) optimality conditions; the interrelationships between various proposed constraint qualifications; and Lagrangian duality and saddle point optimality conditionsAlgorithms and their convergence, with a presentation of algorithms for solving both unconstrained and constrained nonlinear programming problemsImportant features of the "Third Edition" include: New topics such as second interior point methods, nonconvex optimization, nondifferentiable optimization, and moreUpdated discussion and new applications in each chapterDetailed numerical examples and graphical illustrationsEssential coverage of modeling and formulating nonlinear programsSimple numerical problemsAdvanced theoretical exercisesThe book is a solid reference for professionals as well as a useful text for students in the fields of operations research, management science, industrial engineering, applied mathematics, and also in engineering disciplines that deal with analytical optimization techniques. The logical and self-contained format uniquely covers nonlinear programming techniques with a great depth of information and an abundance of valuable examples and illustrations that showcase the most current advances in nonlinear problems.
6,259 citations
"Mode Modulation for Wireless Commun..." refers methods in this paper
...Based on the optimization theory [37], [38], the Lagrangian dual problem to P3 is given by...
[...]
01 Sep 1952
TL;DR: A minimum-redundancy code is one constructed in such a way that the average number of coding digits per message is minimized.
Abstract: An optimum method of coding an ensemble of messages consisting of a finite number of members is developed. A minimum-redundancy code is one constructed in such a way that the average number of coding digits per message is minimized.
5,221 citations
TL;DR: A minimum-redundancy code is one constructed in such a way that the average number of coding digits per message is minimized.
Abstract: An optimum method of coding an ensemble of messages consisting of a finite number of members is developed. A minimum-redundancy code is one constructed in such a way that the average number of coding digits per message is minimized.
3,528 citations
"Mode Modulation for Wireless Commun..." refers methods in this paper
...The main idea of Huffman coding for AMM is to assign binary codes to mode symbols according to the probabilities of mode symbols [35], [36]....
[...]
TL;DR: An application is the construction of a uniformly universal sequence of codes for countable memoryless sources, in which the n th code has a ratio of average codeword length to source rate bounded by a function of n for all sources with positive rate.
Abstract: Countable prefix codeword sets are constructed with the universal property that assigning messages in order of decreasing probability to codewords in order of increasing length gives an average code-word length, for any message set with positive entropy, less than a constant times the optimal average codeword length for that source. Some of the sets also have the asymptotically optimal property that the ratio of average codeword length to entropy approaches one uniformly as entropy increases. An application is the construction of a uniformly universal sequence of codes for countable memoryless sources, in which the n th code has a ratio of average codeword length to source rate bounded by a function of n for all sources with positive rate; the bound is less than two for n = 0 and approaches one as n increases.
1,306 citations
"Mode Modulation for Wireless Commun..." refers methods in this paper
...The main idea of Huffman coding for AMM is to assign binary codes to mode symbols according to the probabilities of mode symbols [35], [36]....
[...]
..., 1 L ] , the AMM scheme is equivalent to the EMM scheme, in which all the mode patterns have equal probability to be activated, regardless of the channel quality corresponding to each OAM mode [35]....
[...]
TL;DR: This work demonstrates a 32-Gbit’s−1 millimetre-wave link over 2.5 metres with a spectral efficiency of ~16 bit s− 1 Hz−1 using four independent orbital–angular momentum beams on each of two polarizations, and shows an 8-Gbits−1 link containing two orbital angular momentum beams with crosstalk less than −12.5 dB.
Abstract: One property of electromagnetic waves that has been recently explored is the ability to multiplex multiple beams, such that each beam has a unique helical phase front. The amount of phase front ‘twisting’ indicates the orbital angular momentum state number, and beams with different orbital angular momentum are orthogonal. Such orbital angular momentum based multiplexing can potentially increase the system capacity and spectral efficiency of millimetre-wave wireless communication links with a single aperture pair by transmitting multiple coaxial data streams. Here we demonstrate a 32-Gbit s−1 millimetre-wave link over 2.5 metres with a spectral efficiency of ~16 bit s−1 Hz−1 using four independent orbital–angular momentum beams on each of two polarizations. All eight orbital angular momentum channels are recovered with bit-error rates below 3.8 × 10−3. In addition, we demonstrate a millimetre-wave orbital angular momentum mode demultiplexer to demultiplex four orbital angular momentum channels with crosstalk less than −12.5 dB and show an 8-Gbit s−1 link containing two orbital angular momentum beams on each of two polarizations. High speed data transmission using orbital angular momentum beams has been recently demonstrated. Here, Yan et al. demonstrate a 32 Gbit/s millimetre-wave communication link using eight coaxially propagating independent orbital angular momentum beams with four orbital angular momentum states on two orthogonal polarizations.
1,002 citations
"Mode Modulation for Wireless Commun..." refers background or methods in this paper
...While many prototypes of OAM based vorticose communications have been implemented recently [19]–[22] and highlighted the attractive advantages of OAM based vorticose communications, such as completely eliminated inter-channel interference (ICI) due to the orthogonality of OAM beams, avoiding additional post-processing overheads compared with MIMO systems, and less stringent antenna synchronization [20]....
[...]
...(19) and (21), are same to the SE of OAM-based wireless communication without MM, in which all the OAM modes are utilized to transfer information [20]....
[...]
...Later, the authors of [20] and [21] realized four OAM modes multiplexing transmissions at microwave band in 2014 and 2017, respectively....
[...]