Minimum Shift Keying Research Articles

Performance Analysis of Modulation Techniques for Indoor Free Space Optics

This paper deals with designing and analyzing the performance of indoor Free Space Optics (FSO) link for various modulation techniques in diffused channel conditions. At the present time, FSO is widely adopted because of its features; high speed, security, low power consumption and unlicensed spectrum. LEDs and LASERs are optimum choice to cater the dynamic range of requirements for optical communication system. The indoor FSO system has been simulated in Optisystem 14 software using various modulation schemes under different attenuation factors which may influence the performance of the system. In this paper, we have analyzed the performance of different modulation schemes such as Return to Zero, Non-Return to Zero, Phase Shift Keying, Pulse Amplitude Modulation, Quadrature Amplitude Modulation and Minimum Shift Keying. This work mainly focuses on the parameters; Bit Error Rate, Q-factor and power corresponding to transmission distance achieve minimum attenuation.

A new derivation of the Nakagami-m distribution as a composite of the Rayleigh distribution

Mobile communications systems are affected by what is known as fading, which is a well-known problem largely studied for decades. The direct consequence of fading is the complete loss of signal (or a large decrease of the received power). Rayleigh fading is a reasonable model for wireless channels although, Nakagami-m distribution seems better suited to fitting experimental data. In this paper we obtain the Nakagami-m distribution as a composite (mixture) of the Rayleigh distribution, a result which as far as we know it has not been shown in the literature. This representation of the Nakagami-m distribution facilitates computations of the average BER (Bit Error Rate) for DPSK (Differential Phase Shift Keying) and MSK (Minimum-Shift Keying) modulations for this distribution and higher moments of them, which is of great applicability to modeling wireless fading channels. Furthermore, a simple, not depending on any special function, apart of the Gamma function, bivariate version of the Nakagami-m distribution is also proposed as a special case of the multivariate version which is also presented. The proposed composite distribution is simulated through the standard procedure of summation of phasors, and results for the new closed-form measures for the MSK modulation are also shown. From that it is clear that the alternative formulation of the Nakagami-m distribution allows for easier modeling of fading fading-shadowing wireless channels through the new explicit second order statistics metrics. is well suited for modelling fading-shadowing wireless channels.

A tactical data link model based on CCSK-FMSK

In collaborative combat operations, the challenges brought by the communication adversities of tactical data links are becoming increasingly prominent. Ensuring the reliable connection of tactical data links has always been a key issue, especially considering the increasing impact of external interference on the signal at the receiving end of the system, which in turn affects the bit error rate (BER) of the tactical data link system. To address this challenge, this paper proposes a tactical data link anti-interference scheme based on cyclic code shift keying (CCSK) spread spectrum and minimum shift keying (MSK) modulation fusion frequency hopping technology, named CCSK-FMSK, and introduces turbo code and cyclic redundancy check (CRC) coding to construct a tactical data link model based on CCSK-FMSK. Specifically, CCSK-FMSK disperses interference power by expanding the signal spectrum, enhancing the anti-interference ability of tactical data links. CRC coding and Turbo coding achieve error detection and correction by introducing supervised symbols. In addition, this paper proposes a soft despreading and a soft demodulation algorithm corresponding to CCSK spread spectrum and MSK modulation to achieve cascade with Turbo decoder and improve the error rate performance and robustness of the model. Compared with existing models, the tactical data link based on CCSK-FMSK has better BER performance.

Frequency modulated signal standing out by stochastic resonance effect

In this paper, the phenomenon which is known as stochastic resonance is considered to the signal processing application. Signal standing out with the presence of noise is considered to be one of the basic problems of telecommunication and radioengineering. The stochastic resonance effect is shown to provide significant improvement of some characteristics of the information signal, such as power gain, and noise dispersion at the system output at a certain optimal noise level. In the present article, Minimum Shift Keying signal mixed with Gaussian white noise has been studied using stochastic resonance effect. Noise coefficient, which is one of the quantitative characteristics of noise immunity is calculated and investigated.

Ultra reliability and massive connectivity provision in integrated internet of military things (IoMT) based on tactical datalink

One of the major challenges arising in internet of military things (IoMT) is accommodating massive connectivity while providing guaranteed quality of service (QoS) in terms of ultra-high reliability. In this regard, this paper presents a class of code-domain nonorthogonal multiple accesses (NOMAs) for uplink ultra reliable networking of massive IoMT based on tactical datalink such as Link-16 and joint tactical information distribution system (JTIDS). In the considered scenario, a satellite equipped with Nr antennas servers K devices including vehicles, drones, ships, sensors, handset radios, etc. Nonorthogonal coded modulation, a special form of multiple input multiple output (MIMO)-NOMA is proposed. The discussion starts with evaluating the output signal to interference-plus-noise (SINR) of receiver filter, leading to the unveiling of a closed-form expression for overloading systems as the number of users is significantly larger than the number of devices admitted such that massive connectivity is rendered. The expression allows for the development of simple yet successful interference suppression based on power allocation and phase shaping techniques that maximizes the sum rate since it is equivalent to fixed-point programming as can be proved. The proposed design is exemplified by nonlinear modulation schemes such as minimum shift keying (MSK) and Gaussian MSK (GMSK), two pivotal modulation formats in IoMT standards such as Link-16 and JITDS. Numerical results show that near capacity performance is offered. Fortunately, the performance is obtained using simple forward error corrections (FECs) of higher coding rate than existing schemes do, while the transmit power is reduced by 6 dB. The proposed design finds wide applications not only in IoMT but also in deep space communications, where ultra reliability and massive connectivity is a keen concern.

COHERENT DEMODULATION OF SYNCHRONOUS MUTUALLY NOT ORTHOGONAL DIGITAL SIGNALS WITH MANIPULATION IN THE MINIMUM SHIFT KEYING

The article presents the synthesis of a mathematical model of the compensation procedure for coherent demodulation of synchronous mutually non-orthogonal digital signals with manipulation in the minimum shift keying. In the absence of interference this procedure degenerates into the procedure of classical coherent demodulation of digital signals with manipulation in the minimum shift keying. With a significant excess of the instantaneous power of interference over the instantaneous power of useful digital signals with manipulation in the minimum shift keying the immunity of reception of the latter approaches the immunity of reception in a channel with additive white Gaussian noise without interference. This mathematical model can be used in the development of modem compensators that ensure repeated use of the frequency resource, as well as in the development of promising interference -protected radio communication devices.

Novel technique to cancel MAI for OCDMA system

Abstract Code division multiple access in optical domain has a potential in next-generation long-haul transmission systems. However, multiple user interference is a snag in functioning of system employing OCDMA. A detailed analysis of multiple access interference (MAI) which causes a severe degradation in the system performance is done in this paper. An optimum MAI cancellation scheme has been proposed. This cancellation scheme depends not only on using the excellent correlation property of the double padded modified prime codes (DPMPC) as spreading sequence but also on employing minimum shift keying (MSK). The performance of the proposed cancellation scheme is compared with the existing techniques of FSK-OCDMA and PPM-OCDMA cancellation techniques. MSK-OCDMA cancellation technique achieves the lowest bit error rate of 10−20. It is also efficient in power. It achieves lowest bit error rate at same number of mean photon number when compared to the existing techniques. The investigations reveal that MSK-OCDMA cancellation technique outperforms FSK-OCDMA and PPM-OCDMA cancellation schemes.

Drone-Aided Networking with Massive Connectivity and High Spectral Efficiency Enabled

Drone-aided networking is considered a potential candidate for internet of things (IoT) networking in 5G and beyond, where drones are deployed to serve a large number of devices simultaneously for data collection, surveillance, remote sensing, etc. However, challenges arise due to massive connectivity requests as well as limited power budgets. To this end, this paper focuses on the design of drone-aided IoT networking, where a drone access point serves a large number of devices for efficient data transmission, collection, and remote sensing. Constant envelope signaling such as minimum shift keying (MSK) family is considered to avoid potential significant power inefficiency due to nonlinear distortion. To this end, code-domain non-orthogonal multiple access (NOMA) is developed and analyzed in terms of achievable sum spectral efficiency. Further, power allocation is derived based on the aforementioned analysis and is demonstrated to offer significantly improved performance in terms of sum spectral efficiency and user load. Simulation results confirm the feasibility of the proposed design and shows that the designed system can attain the promised performance using either simple convolutional code or complex polar code. The proposed system can be used in scenarios such as deep space communications, where MSK family signaling is adopted as well.

GMSK Demodulation Combining 1D‐CNN and Bi‐LSTM Network Over Strong Solar Wind Turbulence Channel

AbstractTo solve the problem of bit error rate (BER) performance degradation over strong solar wind turbulence channel, this paper addresses to Gaussian minimum frequency shift keying (GMSK) demodulation using machine learning. First, by analyzing the scintillation characteristics of the telemetry signal caused by solar wind turbulence during the solar superior conjunction, the K distribution channel model is innovatively established over strong solar wind turbulence channel. Then, the approximate probability density function of the K distribution of the established channel is studied by using Laguerre orthogonal polynomial for convenience. Additionally, the BER performance of GMSK over strong solar wind turbulence channel is analyzed. Second, using a one‐dimensional convolutional neural network (1D‐CNN) and bidirectional long short‐term memory network (Bi‐LSTM), two demodulators for GMSK are proposed. By integrating the 1D‐CNN and LSTM to extract local features and process the dynamic information of GMSK signals, we propose a novel GMSK demodulator over strong solar wind turbulence channel with combining 1D‐CNN and Bi‐LSTM. The simulation results show that, even if the solar wind turbulence has serious effects on the signal at a low signal‐to‐noise ratio, the proposed combining neural network demodulation can obtain better BER performance than the classical Viterbi algorithm, demodulation using only a single 1D‐CNN or Bi‐LSTM. The proposed GMSK demodulator is more suitable for the deep space exploration of the solar system.

PERFORMANCE ANALYSIS OF GMSK-BASED COOPERATIVE COMMUNICATION IN WIRELESS SENSOR NETWORKS

An efficacious energy model based on Gaussian minimum shift keying (GMSK) for cooperative communication is proposed in this paper. The influence of the rate at which data are transmitted, distance, severity of fading, and quantity of participating nodes on the energy expended for communication by the proposed model is investigated through simulations. The influence of the rate at which data are transmitted and the quantity of participating nodes on the energy expended in circuitry is also studied. Through the simulations, it is apparent that the energy consumed by the circuit dominates the energy consumed for transmission for all of the transmission data rates, path loss exponents, bit error rates, and transmission distances considered.

Waveform design and signal processing method for integrated underwater detection and communication system

AbstractFor the integrated system of underwater detection and communication, an emitted waveform should satisfy both detection and communication requirements. The signal processing method at the receiving end must also accomplish target detection and communication accordingly. This study uses a generalised sinusoidal frequency modulated (GSFM) waveform with a carrier to ensure detection performance. At the same time, the communication information encoding with Gaussian Minimum Shift Keying is modulated to the GSFM signal for communication purposes. Unlike previous work, an improved Blind Source Separation algorithm is utilised at the receiving end, which is better adapted to waveform separation and processing in the underwater time‐varying unknown environment. The analysis of detection probability, peak‐to‐average ratio, and signal processing results show that the proposed waveform and corresponding signal processing scheme can effectively meet the need for integrated underwater detection and communication system.

UOWC performance based on GMSK modulation

Abstract This paper studies and investigates the performance of Gaussian minimum shift keying (GMSK) for underwater optical wireless communication (UOWC). Various scatterings may result in inter-symbol interference (ISI) and degrade system error performance in UWOC links. Bit-error rate (BER) is evaluated using different water environment models such as clear seawater, coastal, and harbor for a 20 m link range. Simulation results indicate the BER performance is degraded due to the temporal dispersion of impulse response for high data rates in turbid water. In addition, the bandwidth-symbol time product (BT) is an essential parameter in GMSK, affecting BER performance and power efficiency. Therefore, BT must be chosen with a value that balances BER and power efficiency. The results show that GMSK with BT = 0.5 is a good choice that satisfies BER = 10−5 for SNR = 10 dB with an efficient power spectrum due to constant envelope and low out-of-band radiation.

Analysis of Transmission Characteristics on an MSK-Based Rotating Magnet-Based Mechanical Antenna

A rotating magnet-based mechanical antenna (RMBMA) is a new promising paradigm which can significantly reduce both the size and the power consumption of the super-low frequency electromagnetic transmitter. To further reveal the effects of the rotational motion on transmission, this paper investigates the performance analysis of MSK (Minimum Shift Keying)-based RMBMA for the first time. Initially, based on the framework of MSK-based RMBMA, both the information loading of RMBMA and the control strategies of the motor are proposed, such that the impacts of the step response induced by the motor on the information loading are characterized. Then, the transmission capacity of the MSK-based RMBMA is derived in the closed form. The results indicate that increasing output torque or decreasing inertia load can enhance the transmission capacity. Finally, numerical simulations using a realistic system model demonstrate the validity of the proposed performance analysis. The simulation results show that when the inertia is less than 0.0128 kg∙m2 and the symbol rate is less than 4 bit/s, the bit error rate is less than 10%, thereby improving the transmission capacity. The proposed comprehensive design principles of RMBMA provide guidance for system design and practical implementation.

Prefiltered Single-Carrier Frequency-Domain Equalization for Binary CPM over Shallow Water Acoustic Channel

The continuous phase modulation (CPM) technique is an excellent solution for underwater acoustic (UWA) channels with limited bandwidth and high propagation attenuation. However, the severe intersymbol interference is a big problem for the algorithm applying in shallow water. To solve this problem, an algorithm for prefiltered single-carrier frequency-domain equalization (PF-SCFDE) is presented in this paper. The regular whitening filter is replaced by a prefilter in the proposed algorithm. The output information sequence of this prefilter contains the forward information. To improve the performance, the output of the equalizer, combined with the forward information, is used to make the maximum likelihood estimation. The simulation results with minimum-shift keying and Gaussian-filtered minimum-shift keying signals over shallow water acoustic channels with low root mean square delay spread demonstrate that PF-SCFDE outperformed the traditional single-carrier frequency-domain equalization (SCFDE) by approximately 1 dB under a bit error rate (BER) of 10−4. A shallow sea trial has demonstrated the effectiveness of PF-SCFDE; PF-SCFDE had a reduction in BER of 18.35% as compared to the traditional SCFDE.

Design of a Robust Orthogonal Frequency Division Multiplexing (OFDM) Transceiver for a Cognitive Radio Testbed

Primarily, a Cognitive Radio (CR) resolves the problem of spectrum scarcity and underutilization. However, it should also attain a good throughput and Quality of Service (QoS) as its objectives. These requirements are solely dependent on the modulation used. Though single carrier modulations such as Gaussian Minimum Shift Keying (GMSK) are highly spectral efficient, they are not robust to frequency selective fading. An implementation of multicarrier modulation supports high spectral efficiency and resistance to multipath fading. Therefore, in this paper, there is a comprehensive how-to-guide of the design of Orthogonal Frequency Division Multiplexing (OFDM) in cognitive radio using GNU Radio (GR) 3.8 that interfaces with Universal Software Radio Peripheral (USRP) B210s for video transmission. The implementation achieved allows for the choice of any modulation schemes out of four commonly used ones for communication of the payloads thus offering dynamism for use in a cognitive radio system. The effective implementation of the proposed methods in this paper is verified by the successful transmission and reception of a 4 minute 37 seconds MP4 video across the different choices of modulation schemes. It was observed that the error performance of the payloads degraded with higher constellation points however, the throughput was increased. Hence, the trade-off between error probability and throughput in the cognitive radio is based on the radio-scene metrics about the signal-to-noise ratio (SNR) of the available channels.

Joint Radar-Communication Relying on NLFM-MSK Design

The existing joint radar-communication (JRC) based on linear frequency modulation (LFM) is imperfect because of high autocorrelation sidelobe and poor nearby target detection performance. This paper proposes a JRC signal based on the non-LFM (NLFM) wave by using minimum shift keying (MSK). Then, this paper analyzes the performance of ambiguity function (AF) characteristics, detection probability, time-frequency characteristics, and communication rate for the proposed JRC signal. It is concluded that the proposed JRC signal has both excellent radar and communication characteristics. Under the condition of low data volume, the simulation results illustrate that (i) compared with the existing LFM-MSK signal, our JRC signal’s sidelobe level of the time AF is significantly lower; the range resolution is improved significantly; (ii) the proposed JRC signal has no loss on velocity resolution and detection probability; and (iii) the proposed JRC signal has excellent time-frequency characteristics.

Joint time-frequency domain equalization of MSK signal over underwater acoustic channel

Minimum shift keying (MSK) shows better bandwidth efficiency than the phase shift keying owing to its high bandwidth usage efficiency and constant envelope property. The performance of frequency-domain block linear equalization (FD-BLE), which is commonly used for MSK communication, is limited in complex time-varying underwater acoustic (UWA) channel. In this paper, a time-domain adaptive decision feedback equalization (TD-ADFE) is proposed to address issues pertaining to MSK communications over UWA channel. Further joint time–frequency domain equalization (JTFDE) built on TD-ADFE and BLE is proposed to further reduce the bit error rate (BER). The proposed method can effectively track the time-varying UWA channel through the updated equalizer coefficient according to the output of de-mapper. Numerical simulation shows that the JTFDE performed better than TD-ADFE and FD-BLE over time-varying UWA channel by approximately 2 dB when the BER was 1 × 10−3.The sea trial results verified the proposed JTFDE and demonstrated that the BER of JTFDE was 82.5% and 88.9% lower than that of TD-ADFE and FD-BLE, respectively.

Research on long distance submarine optical fiber transmission system using MSK downlink signals

The commonly used submarine optical fiber communication system is expected to provide long-distance reliable signals transmission. We present a novel optical fiber submarine system using minimum shift keying (MSK) encoded downstream signals. 10Gb/s MSK coded signals are successfully transmitted over the 100km submarine single-mode fiber (SMF).The optical spectrums, eye-diagrams and bit error rate (BER) before and after transmission of MSK signals in the system were measured and analyzed. The results show that, compared with conventional access methods, this scheme can provide high-speed, stable and secure data communication.

A GMSK/PAM4 Multichannel Magnetic Human Body Communication Transceiver

This letter presents a dual-mode multichannel transceiver implemented with low path loss offered by magnetic human body communication (mHBC) toward ultraefficient body-area networking. Two spectral-efficient modulation schemes: 1) Gaussian minimum-shift keying (GMSK) and 2) 4-level pulse-amplitude modulation (PAM4), are used to reduce interference on adjacent channels. A power oscillator is used to efficiently generate both GMSK- and PAM4-modulated magnetic fields while multichannel selection is implemented by on-chip capacitor tuning and an analog PLL, enabling 5 and 10 Mb/s data for GMSK and PAM4, respectively. The transmitter achieves an efficiency of 15.5 and 19.4 pJ/bit, while the receiver consumes 4.6 and 2.7 pJ/bit for GMSK and PAM4, respectively.

A new ABER approximation of FSO system using PPM–GMSK hybrid modulation scheme under weak turbulence

In this paper, free space optical communication system (FSO) employing a hybrid modulation technique called pulse position modulation–Gaussian minimum shift keying (PPM–GMSK) technique, is investigated by considering log–normal as the channel fading statistics under weak turbulence. The analytical average bit error rate (ABER) and closed form expression of the proposed hybrid modulation scheme are derived. Simulation results depict the excellent agreement of the derived closed form expression with those obtained using Gauss–Hermite approximation and with the Monte Carlo simulations.