Joint time-frequency DMRS design for high mobility LTE-A V2V communication systems

Blind modulation classification is an important step in implementing cognitive radio networks. The multiple-input multiple-output (MIMO) technique is widely used in military and civil communication systems. Due to the lack of prior information about channel parameters and the overlapping of signals in MIMO systems, the traditional likelihood-based and feature-based approaches cannot be applied in these scenarios directly. Hence, in this paper, to resolve the problem of blind modulation classification in MIMO systems, the time–frequency analysis method based on the windowed short-time Fourier transform was used to analyze the time–frequency characteristics of time-domain modulated signals. Then, the extracted time–frequency characteristics are converted into red–green–blue (RGB) spectrogram images, and the convolutional neural network based on transfer learning was applied to classify the modulation types according to the RGB spectrogram images. Finally, a decision fusion module was used to fuse the classification results of all the receiving antennas. Through simulations, we analyzed the classification performance at different signal-to-noise ratios (SNRs); the results indicate that, for the single-input single-output (SISO) network, our proposed scheme can achieve 92.37% and 99.12% average classification accuracy at SNRs of −4 and 10 dB, respectively. For the MIMO network, our scheme achieves 80.42% and 87.92% average classification accuracy at −4 and 10 dB, respectively. The proposed method greatly improves the accuracy of modulation classification in MIMO networks.

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Multi-Domain Communication Systems and Networks: A Tensor-Based Approach

Network ◽

10.3390/network1020005 ◽

2021 ◽

Vol 1 (2) ◽

pp. 50-74

Author(s):

Divyanshu Pandey ◽

Adithya Venugopal ◽

Harry Leib

Keyword(s):

Communication Systems ◽

Physical Layer ◽

Mathematical Framework ◽

Trade Off ◽

Information Theoretic ◽

Time Frequency ◽

Tensor Formulation ◽

Processing Techniques ◽

Multiple Domains ◽

Signal Processing Techniques

Most modern communication systems, such as those intended for deployment in IoT applications or 5G and beyond networks, utilize multiple domains for transmission and reception at the physical layer. Depending on the application, these domains can include space, time, frequency, users, code sequences, and transmission media, to name a few. As such, the design criteria of future communication systems must be cognizant of the opportunities and the challenges that exist in exploiting the multi-domain nature of the signals and systems involved for information transmission. Focussing on the Physical Layer, this paper presents a novel mathematical framework using tensors, to represent, design, and analyze multi-domain systems. Various domains can be integrated into the transceiver design scheme using tensors. Tools from multi-linear algebra can be used to develop simultaneous signal processing techniques across all the domains. In particular, we present tensor partial response signaling (TPRS) which allows the introduction of controlled interference within elements of a domain and also across domains. We develop the TPRS system using the tensor contracted convolution to generate a multi-domain signal with desired spectral and cross-spectral properties across domains. In addition, by studying the information theoretic properties of the multi-domain tensor channel, we present the trade-off between different domains that can be harnessed using this framework. Numerical examples for capacity and mean square error are presented to highlight the domain trade-off revealed by the tensor formulation. Furthermore, an application of the tensor framework to MIMO Generalized Frequency Division Multiplexing (GFDM) is also presented.

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Modeling of Non-WSSUS Double-Rayleigh Fading Channels for Vehicular Communications

Wireless Communications and Mobile Computing ◽

10.1155/2017/6394653 ◽

2017 ◽

Vol 2017 ◽

pp. 1-15 ◽

Cited By ~ 4

Author(s):

Carlos A. Gutiérrez ◽

J. J. Jaime-Rodríguez ◽

J. M. Luna-Rivera ◽

Daniel U. Campos-Delgado ◽

Javier Vázquez Castillo

Keyword(s):

Fading Channels ◽

Communication Systems ◽

Rayleigh Fading ◽

Channel Model ◽

Closed Form Solution ◽

Multipath Fading ◽

Rayleigh Distribution ◽

Rayleigh Fading Channels ◽

Small Scale ◽

Time Frequency

This paper deals with the modeling of nonstationary time-frequency (TF) dispersive multipath fading channels for vehicle-to-vehicle (V2V) communication systems. As a main contribution, the paper presents a novel geometry-based statistical channel model that facilitates the analysis of the nonstationarities of V2V fading channels arising at a small-scale level due to the time-varying nature of the propagation delays. This new geometrical channel model has been formulated following the principles of plane wave propagation (PWP) and assuming that the transmitted signal reaches the receiver antenna through double interactions with multiple interfering objects (IOs) randomly located in the propagation area. As a consequence of such interactions, the first-order statistics of the channel model’s envelope are shown to follow a worse-than-Rayleigh distribution; specifically, they follow a double-Rayleigh distribution. General expressions are derived for the envelope and phase distributions, four-dimensional (4D) TF correlation function (TF-CF), and TF-dependent delay and Doppler profiles of the proposed channel model. Such expressions are valid regardless of the underlying geometry of the propagation area. Furthermore, a closed-form solution of the 4D TF-CF is presented for the particular case of the geometrical two-ring scattering model. The obtained results provide new theoretical insights into the correlation and spectral properties of small-scale nonstationary V2V double-Rayleigh fading channels.

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On the Statistical Analysis of the Channel Capacity of Double Rayleigh Channels with Equal Gain Combining in V2V Communication Systems

2010 IEEE 71st Vehicular Technology Conference ◽

10.1109/vetecs.2010.5494112 ◽

2010 ◽

Cited By ~ 4

Author(s):

Batool Talha ◽

Matthias Patzold

Keyword(s):

Statistical Analysis ◽

Channel Capacity ◽

Communication Systems ◽

Equal Gain Combining ◽

V2v Communication ◽

Rayleigh Channels

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Three-Dimensional MIMO Channel Model with High-Mobility Wireless Communication Systems Using Leaky Coaxial Cable in Rectangular Tunnel

International Journal of Antennas and Propagation ◽

10.1155/2021/6622135 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Kai Zhang ◽

Fangqi Zhang ◽

Guoxin Zheng ◽

Lei Cang

Keyword(s):

Wireless Communication ◽

Communication Systems ◽

Channel Model ◽

Mimo System ◽

Three Dimensional ◽

High Mobility ◽

Coaxial Cable ◽

Mimo Channel ◽

Wireless Communication Systems ◽

Rectangular Tunnel

With the rapid development of high-mobility wireless communication systems, e.g., high-speed train (HST) and metro wireless communication systems, more and more attention has been paid to the wireless communication technology in tunnel-like scenarios. In this paper, we propose a three-dimensional (3D) nonstationary multiple-input multiple-output (MIMO) channel model with high-mobility wireless communication systems using leaky coaxial cable (LCX) inside a rectangular tunnel over the 1.8 GHz band. Taking into account single-bounce scattering under line-of-sight (LoS) and non-line-of-sight (NLoS) propagations condition, the analytical expressions of the channel impulse response (CIR) and temporal correlation function (T-CF) are derived. In the proposed channel model, it is assumed that a large number of scatterers are randomly distributed on the sidewall of the tunnel and the roof of the tunnel. We analyze the impact of various model parameters, including LCX spacing, time separation, movement velocity of Rx, and K-factor, on the T-CF of the MIMO channel model. For HST, the results of some further studies on the maximum speed of 360 km/h are given. By comparing the T-CF between the dipole MIMO system and the LCX-MIMO system, we can see that the performance of the LCX-MIMO system is better than that of the dipole MIMO system.

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Orthogonal Time Sequency Multiplexing Modulation

10.36227/techrxiv.13580201.v1 ◽

2021 ◽

Author(s):

Tharaj Thaj ◽

Emanuele Viterbo

Keyword(s):

Time Domain ◽

Orthogonal Frequency Division Multiplexing ◽

High Performance ◽

High Mobility ◽

Low Complexity ◽

Modulation Scheme ◽

Frequency Space ◽

Time Frequency ◽

Single Carrier ◽

The Time Domain

This paper proposes <i>orthogonal time sequency multiplexing</i> (OTSM), a novel single carrier modulation scheme based on the well known Walsh-Hadamard transform (WHT) combined with row-column interleaving, and zero padding (ZP) between blocks in the time-domain. The information symbols in OTSM are multiplexed in the delay and sequency domain using a cascade of time-division and Walsh-Hadamard (sequency) multiplexing. By using the WHT for transmission and reception, the modulation and demodulation steps do not require any complex multiplications. We then propose two low-complexity detectors: (i) a simpler non-iterative detector based on a single tap minimum mean square time-frequency domain equalizer and (ii) an iterative time-domain detector. We demonstrate, via numerical simulations, that the proposed modulation scheme offers high performance gains over orthogonal frequency division multiplexing (OFDM) and exhibits the same performance of orthogonal time frequency space (OTFS) modulation, but with lower complexity. In proposing OTSM, along with simple detection schemes, we offer the lowest complexity solution to achieving reliable communication in high mobility wireless channels, as compared to the available schemes published so far in the literature.

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