Differential Binary Phase Shift Keying Research Articles

Performance of Reconfigurable-Intelligent-Surface-Assisted Satellite Quasi-Stationary Aircraft–Terrestrial Laser Communication System

This paper proposes the use of quasi-stationary aircraft and reconfigurable intelligent surfaces (RIS) to improve the system performance in satellite–terrestrial laser communication downlink. Single-input multiple-output (SIMO) technology is applied to the relay node of a quasi-stationary aircraft. The closed expression of the bit error rate (BER) of an RIS-assisted satellite quasi-stationary aircraft–terrestrial laser communication system (RIS-SHTLC) is derived under the M-distributed atmospheric turbulence model while considering the influence of atmospheric turbulence and pointing errors caused by RIS jitter. The effects of coherent binary frequency shift keying (CBFSK), coherent binary phase-shift keying (CBPSK), non-coherent binary frequency shift keying (NBFSK), and differential binary phase-shift keying (DBPSK) on the performance of an RIS-SHTLC system are simulated and analyzed under weak turbulence. The results show that the RIS-SHTLC system with CBPSK modulation has the best communication performance. Simultaneously, the relationships between the average signal-to-noise ratio (SNR) and BER of the RIS-SHTLC system under different RIS elements are simulated and analyzed, and compared with the traditional SHTLC system. In addition, the influence of the zenith angle, receiving aperture and divergence angle on the performance of the system is studied. Finally, Monte Carlo simulations are used to validate the analytical results.

A Design of Analog Front-End with DBPSK Demodulator for Magnetic Field Wireless Network Sensors

This paper presents an on-chip fully integrated analog front-end (AFE) with a non-coherent digital binary phase-shift keying (DBPSK) demodulator suitable for short-range magnetic field wireless communication applications. The proposed non-coherent DBPSK demodulator is designed based on using comparators to digitize the received differential analog BPSK signal. The DBPSK demodulator does not need any phase-lock loop (PLL) to detect the data and recover the clock. Moreover, the proposed demodulator provides the detected data and the recovered clock simultaneously. Even though previous studies have offered the basic structure of the AFEs, this work tries to amplify and generate the required differential BPSK signal without missing data and clock throughout the AFE, while a low voltage level signal is received at the input of the AFE. A DC-offset cancellation (DCOC), a cascaded variable gain amplifier (VGA), and a single-to-differential (STOD) converter are employed to construct the implemented AFE. The simulation results indicate that the AFE provides a dynamic range of 0 dB to 40 dB power gain with 2 dB resolution. Measurement results show the minimum detectable voltage at the input of AFE is obtained at 20 mV peak-to-peak. The AFE and the proposed DBSPK demodulator are analyzed and fabricated in a 130 nm Bipolar-CMOS-DMOS (BCD) technology to recover the maximum data rate of 32 kbps where the carrier frequency is 128 kHz. The implemented DCOC, cascaded VGA, STOD, and the demodulator occupy 0.15 , 0.063 , 0.045 , and 0.03 of area, respectively. The AFE and the demodulator consume 2.9 mA and 0.15 mA of current from an external 5 V power supply, respectively.

Single Wavelength Simultaneous Optical Intensity-Polarization-Phase Modulation for Multi-Dimensional Optical Transmission

We propose a novel multi-dimensional optical transmission system based on a direct detection system. In the proposed system, quadrature phase shift keying (QPSK), binary polarized intensity rotational frequency shift keying (PIRBFSK), and binary differential phase shift keying (DBPSK) signals modulated by optical intensity, polarization, and phase are simultaneously transmitted for optical multi-dimensional transmission. The signal transmission performance of the proposed modulation technique and the possible interference of each dimension modulation were numerically and experimentally analyzed. The performance of the proposed system was verified using the bit error rate (BER), eye diagram, and spectrum of the received multi-dimensional signal.

A Low-Complexity Underwater Acoustic Coherent Communication System for Small AUV

While underwater acoustic (UWA) communication offers a practical way to establish a wireless link with underwater vehicles, designing a UWA communication system onboard a small autonomous underwater vehicle (AUV) still poses significant challenges. As the adoption of the low-complexity, robust noncoherent communication technology is limited by low bandwidth efficiency and a low data rate, coherent UWA communication requires Doppler mitigation and channel equalization measures to achieve a relatively high data rate in a moving state. Due to the strict constraints of a small-scale AUV in terms of resources and energy consumption, it is not appropriate to use high-complexity Doppler/multipath compensation technology from the prospect of system implementation. In this paper, an efficient and low-complexity UWA differential binary phase-shift keying (DBPSK) system onboard a small AUV is proposed by simplifying the Doppler and multipath compensation. Specifically, for Doppler, the delay of the adjacent DBPSK symbols is calculated according to the Doppler estimate to facilitate delay-tuning Doppler correction. For multipath, low-complexity LMS channel equalization is incorporated with error correction coding to enable multipath mitigation. With a simple structure and low computational complexity, the proposed scheme facilitates the practical hardware implementation and system integration in the small AUV platform. The numerical simulations are conducted to assess the validity of the proposed scheme under different channel conditions and the effectiveness of the proposed scheme is further verified by two UWA communication field tests, which are performed at a practical shallow water sea and lake, respectively.

Dynamic drill-string modeling for acoustic telemetry

Directional drilling techniques require real-time sensing of the drill bit direction and the downhole environment from the measurement-while-drilling (MWD) sensor module. Traditional telemetry methods such as the mud-pulse telemetry are limited to low transmission rates. Acoustic telemetry is a method used for transmitting downhole sensor data and it is orders of magnitude faster than conventional telemetry techniques. However, the selection of appropriate carrier frequencies is critically important to transmit measured data. This study proposes a finite element (FE) model based on the Timoshenko beam theory that predicts dynamics of a drill-string over a wide frequency range and boundary condition. Additionally, a modulated acoustic transmission is developed and performed using the determined carrier frequencies. The signal is modulated using differential binary phase shift keying (DBPSK) and is up-converted to the carrier frequency used for the excitation of the drill-string. Packets of bits are first generated as the telemetry data and then convolutionally encoded to reduce errors at the receiver. The receiver at the surface demodulates and decodes the received acceleration signals to recover the transmitted bits through a digitally implemented lock-in amplifier (LIA). Finally, the transmitted and received bits are compared to calculate the bit-error rate (BER) for each signal-to-noise ratio (SNR) condition. By using the LIA, the receiver can extract severely attenuated acoustic signals, but the dynamics of the drill-string and the additional borehole interactions can degrade the performance of the acoustic telemetry system.

Multi-Valued Automatic Cab Signalling System Based on the CDMA Technology

Purpose. The work is aimed at the development of principles for the construction of multi-valued automatic cab signalling system (ACS) using the wide-band pseudorandom signals. Methodology. An analysis of existing ACS systems and modern telecommunication technologies has been performed to achieve the stated purpose. The multi-valued automatic cab signalling system CDMA-ACS has been proposed. The mentioned system utilizes wide-band pseudo-noise signals to transmit commands. System parameters: frequency band – 155...395 Hz, pseudorandom codes – 16-bit Walsh codes, spectrum spreading factor – 16, source signal bandwidth – 15 Hz, carrier modulation – DBPSK (differential binary phase-shift keying), information rate – 15 bit/sec, code combination length – 4 bits, maximum amount of commands – 256, the duration of single command transmission – 0.27 sec. Functional diagrams of generator and receiver of the multi-valued automatic cab signalling system have been designed. It has been suggested to apply the correlation method to receive the ACS signals. Findings. To investigate the proposed CDMA-ACS system the simulation modelling has been accomplished in MATLAB in two stages: at the first stage, the CDMA-ACS system was investigated as disturbance-free; at the second stage – under the influence of powerful narrow-band disturbances (traction current harmonics). It has been found that the system shows high immunity to narrow-band harmonic disturbances. The most significant harmonics of the traction current related to the system are 250 Hz and 300 Hz, since they are the closest to the carrier frequency of 275 Hz. It has been determined that errors in decoding the ACS commands occur if the signal-to-noise ratio becomes lower than -8 dB. To reduce the influence of 250 Hz and 300 Hz, harmonics the application of additional band-reject filters was proposed. Originality. For the first time, the authors of this work carried out research on the multi-valued automatic cab signalling system with the use of wide-band pseudo-random Walsh codes. Practical value. Implementation of solutions being proposed allows improving the informativeness and interference immunity for the automatic cab signalling system, reducing the duration of command transmission from the railway track to the cab.

An Ultralow-Power OOK/BFSK/DBPSK Wake-Up Receiver Based on Injection-Locked Oscillator

This article presents a high-sensitivity and high energy efficiency wake-up receiver (WuRx) based on an injection-locked oscillator (ILO) and an envelope detector to provide the capabilities of reliable demodulation for ON-OFF keying (OOK), binary frequency shift keying (BFSK), and differential binary phase shift keying (DBPSK) demodulation schemes. A 54- μW 433-MHz multimode WuRx is implemented in a 0.18- μm CMOS process. For a data rate of 200 kb/s and a bit error rate (BER) <; 0.1%, the receiver achieves sensitivities of -80/-78/-77 dBm under the OOK/BFSK/DBPSK demodulation schemes, respectively. Furthermore, incorporating an external loop antenna with a reception of an ILO, the receiver features a low-power mode of just 11 μW with a sensitivity of at least -71 dBm.

Energy consumption study of channel access modes and modulation schemes of the 2.4 GHz narrowband IEEE 802.15.6

Energy efficiency is an important challenge for wireless body area networks. Therefore, choosing the channel access modes and modulation schemes that guarantee lower energy consumption is necessary to increase the network lifetime, especially in &lt;em&gt;wireless body area network&lt;/em&gt; (WBAN) medical applications. The purpose of this paper is to analyze the network energy consumption in on-body medical applications (which are classified as low data rate, medium data rate, and high data rate applications) for two channel access mechanisms: random and scheduled access modes, and two modulation schemes: differential quadrature phase shift keying (DQPSK) and differential binary phase shift keying (DBPSK), which are supported by the 2.4 GHz band of the Institute of Electrical and Electronics Engineers (IEEE) 802.15.6 standard. The considered on-&lt;em&gt;body &lt;/em&gt;area network (BAN) of the study supports two communication scenarios: the line-of-sight transmission and the non-line-of-sight communications, referenced as CM3A and CM3B path loss models respectively. Simulation results have demonstrated that the scheduled access mode based on time-division multiple access (TDMA), and DQPSK are the optimal choices to be made at the media access control (MAC) and physical layer levels respectively, in terms of energy efficiency, in low, medium, and high data rate on-body WBAN applications.

Short-Time Spot Communication Using COTS Stereo Speaker

In this paper, we construct the spot communication method using a stereo speaker. In our proposed method, one speaker transmits differential binary phase-shift keying (DBPSK) symbols for communication, and the other speaker transmits sine waves whose frequency is close to that of the DBPSK symbols for jamming. Inside the spot, the jamming signal is canceled by the orthogonality of the communication symbols and jamming signals. Outside the spot, the jamming signal inverts the differential phase of the communication symbols, which prevents normal DBPSK demodulation rendering the communication symbols concealed in the area. This enables correct demodulation only inside the spot. In the conventional method using a stereo speaker, the effect of the jamming signal is weak; thus, transmitting at least 11 symbols is required. In our proposed method, the effective jamming using the interference between sine waves of close frequencies enables spot communication by transmitting only 3 symbols. In the evaluation experiments, we generate the spot from -10 to 20 degrees in a real environment and measure the signals at 9 positions inside and outside the spot, from -40 to 40 degrees at 10 degree intervals. The measurements were conducted 100 times at each position. Through these experiments, we confirmed that demodulation errors occur only outside the spot. In the measurement results, some systematic errors of the differential phase were observed inside the spot, where theoretically this error should not occur. To discuss this error, we conducted additional experiments and revealed the causes.

Performance of Electromagnetic Nanonetwork under relaying for plant monitoring

Recently, Nanonetworks has been envisioned as a predominant technology. Applications of whose ranges from environment to agriculture and biomedical to military, almost in every field of human life. It plays a vital role in crop monitoring for high-resolution agriculture and in detection of emitted volatile organic compounds. However, sensing range of an individual nanosensor is limited. Multi-hop, relay system can be used to enhance the transmission range of nanosensor based Nanonetworks. This manuscript presents various performance measure of an Electromagnetic Nanonetworks under Amplify-and-Forward (AF) relaying for plant monitoring. Specifically, proposes closed form expressions for Average Error Rate and Spectral Efficiency (SE) of Differential Binary Phase Shift Keying (DBPSK) and Differential Quadrature Phase Shift Keying (DQPSK) modulation schemes of Nanonetworks under dual AF relaying. It is worthful to mention that plant scenarios and hence fading model for different types of plant is different. Therefore, in analysis fading channel from source to relay (S-R) is taken as Fox’s H (FH) function which realizes different fading models, such as EGK, Fisher-Snedecor (FS) distribution and Alpha-Mu fading models, as its special cases to represent different plant scenarios. Whereas, fading model from relay to destination (R-D) is taken as Generalized-Gamma (GG). It is observed that an increase in the value of severity and/or shaping parameters decreases the average error rate. On the other hand, converse is true for the spectral efficiency. Analytical results show perfect agreement with simulation.

A Multi-Mode ULP Receiver Based on an Injection-Locked Oscillator for IoT Applications

This paper presents an ultra-low-power receiver based on the injection-locked oscillator (ILO), which is compatible with multiple modulation schemes such as on-off keying (OOK), binary frequency-shift keying (BFSK), and differential binary phase-shift keying (DBPSK). The receiver has been fabricated in 0.18- $\mu \text{m}$ CMOS technology and operates in the ISM band of 2.4 GHz. A simple envelope detection can be used even for the demodulation of BFSK and DBPSK signals due to the conversion capability of the ILO from the frequency and phase to the amplitude. In the proposed receiver, a $Q$ -enhanced single-ended-to-differential amplifier is employed to provide high-gain amplification as well as narrow band-pass filtering, which improves the sensitivity and selectivity of the receiver. In addition, a gain-control loop is formed in the receiver to maintain constant lock range and hence frequency-to-amplitude conversion ratio for the varying power of the BFSK-modulated receiver input signal. The receiver achieves the sensitivity of −87, −85, and −82 dBm for the OOK, BFSK, and DBPSK signals respectively at the data rate of 50 kb/s and the BER lower than 0.1% while consuming the power of $324~\mu \text{W}$ in total.

Mutual Coexistence in WBANs: Impact of Modulation Schemes of the IEEE 802.15.6 Standard

Due to the mobility of subjects carrying wireless Body Area Networks (WBANs), a BAN may be found in an environment that contains other adjacent BANs, which may influence its proper functioning. The purpose of this paper is to study the effect of interference between adjacent BANs on the performance of a reference BAN in terms of packet loss rate (PLR), while considering the following four parameters: the distance separating adjacent BANs, the number of nodes and traffic payload of an interferer BAN, and the transmission data rate. The study is conducted for the two modulation schemes proposed by the IEEE 802.15.6 standard in the 2.4 GHz narrow band, which are: Differential Binary Phase Shift Keying (DBPSK) modulation and Differential Quadrature Phase Shift Keying (DQPSK) modulation. Simulation results have shown that the adoption of a lower-order modulation such as DBPSK can reduce the effect of interference among adjacent BANs.

Performance Analysis and Resource Allocations for a WPCN With a New Nonlinear Energy Harvester Model

Wireless powered communication networks (WPCNs) are commonly analyzed by using the linear energy harvesting (EH) model. However, since practical EH circuits are non-linear, the use of the linear EH model gives rise to distortions and mismatches. To overcome these issues, we propose a more realistic, nonlinear EH model. The model is based upon the error function and has three parameters. Their values are determined to best fit with measured data. We also develop the asymptotic version of this model. For comparative evaluations, we consider the linear and rational EH models. With these four EH models, we investigate the performance of a WPCN. It contains a multiple-antenna power station (PS), a signal-antenna wireless device (WD), and a multiple-antenna information receiving station (IRS). The WD harvests the energy broadcast by the PS in the PS-WD link, and then it uses the energy in the WD-IRS link to transfer information. We analyze the average throughput of delay-limited and delay-tolerant transmission modes as well as the average bit error rate (BER) of binary phase-shift keying (BPSK) and binary differential phase-shift keying (BDPSK) over the four EH modes. As well, we derive the asymptotic expressions for the large PS antenna case and the effects of transmit power control. Furthermore, for the case of multiple WDs, we optimize energy beamforming and time allocation to maximize the minimum rate of the WDs. Finally, the performances of four EH models are validated by Monte-Carlo simulations.

Low-Power Ultrasonic Front End for Cargo Container Monitoring

A low-power ultrasonic communication front end conceived for cargo container monitoring is presented. Two piezoelectric transducers (PTs) operating at 40 kHz are fixed to the metallic wall by means of a customized magnetic case, allowing a noninvasive inside–outside communication preserving the container integrity. Once the resulting ultrasonic channel is characterized, an experimental measurement setup based on field-programmable gate array (FPGA) is implemented for testing some basic modulation and detection schemes in terms of bit error rate (BER), also considering their robustness against undesired mechanical and electromagnetic perturbations. On this basis, a compact digital differential binary phase-shift keying (DBPSK) modulator using a square carrier signal is proposed. Frequency and amplitude tracking algorithms are designed for optimizing the quality and robustness of the data transmission. Finally, a low-power low-rate (up to few kb/s) architectures based on the previous elements are presented. All the proposed contributions are experimentally validated.

Performance analysis of multiple access relay channels for non-coherent modulations

One of the most important applications of network coding is the Multiple Access Relay Channel (MARC) technique in which source terminals transmit independent data blocks over one or more relay terminals to a common destination terminal. In recent years, MARC has become one of the vital network coding applications in the area of innovative wireless cooperative communications for enhancing spectral efficiency. In this paper, non-coherent binary frequency shift keying (BFSK) modulation and differential binary phase shift keying (DPSK) modulation techniques are applied to the decode-and-forward (DF)-based MARC model and the average bit error rate (BER) of the proposed system is derived theoretically by using the maximum likelihood (ML) decision rule. The simulation results show that the BER performance of DPSK modulation is better than the non-coherent BFSK and full diversity gain is achieved in both modulation techniques. We also propose a power allocation scheme for the proposed system model which optimizes the power allocated to the source and relay transmissions. Depending on the location of the relay, performance gains up to 1.25 dB are achieved with the proposed optimum power allocation (OPA) scheme. Also, the mathematical derivations are verified through Monte-Carlo simulations and the superior performance of the OPA over equal power allocation (EPA) is observed.

Noncoherent Detection With Polar Codes

Polar codes (PCs) have attracted significant attention in the last decade, especially after their adoption in the forthcoming 5G wireless networks. However, previous studies focused on coherent polar codes, which always rely on the strong assumption of available perfect channel state information. Instead, in this paper, we investigate the use of PCs in noncoherent systems. First, a binary differential phase shift keying (BDPSK) demodulator is concatenated with a polar decoder to form the noncoherent detector, where successive cancellation (SC) is applied. The simulation results demonstrate that the SC-based PCs for noncoherent detection have approximately a discrepancy of only 3 dB compared with the coherent counterpart in noncoherent channels. Furthermore, in order to further decrease this discrepancy, we replace the BDPSK demodulator with a soft-input soft-output (SISO) multiple symbol differential sphere decoding demodulator. Similarly, the SC-based PC decoder is replaced by the SISO belief propagation-based PC decoder, and by using this novel architecture, an iterative noncoherent detector is constructed. Benefiting from further invoking extrinsic information transfer chart tool and the dynamic window-size detection scheme, the performance of the proposed iterative noncoherent detector becomes competitive with its coherent one in practical applications, since the performance degradation is reduced to 1 dB.

Coverage, Capacity, and Error Rate Analysis of Multi-Hop Millimeter-Wave Decode and Forward Relaying

In this paper, we analyze the end-to-end (e2e) performance of a millimeter-wave (mmWave) multi-hop relay network. The relays in it are decode-and-forward (DF) type. As appropriate for mmWave bands, we incorporate path loss and blockages considering the links to be either line of sight (LOS) or non line of sight (NLOS). The links also experience Nakagami-m fading with different m-parameters for the LOS and NLOS states. We consider two scenarios, namely sparse and dense deployments. In the sparse case, the nodes (relays and the destination) are limited by additive noise only. We derive closed-form expressions for the distribution of equivalent e2e signal-to-noise-ratio (SNR), coverage probability, ergodic capacity, and symbol error rate (SER) for the three classes of digital modulation schemes, namely, binary phase shift keying (BPSK), differential BPSK (DBPSK), and square-quadrature amplitude modulation (QAM). In the dense case, the nodes are limited by interference only. Here, we consider two situations: 1) interference powers are independent and identically distributed (i.i.d.) and 2) they are independent but not identically distributed (i.n.i.d.). For the latter situation, closed-form analysis is exceedingly difficult. Therefore, we use the Welch-Satterthwaite Approximation for the sum of Gamma variables to derive the distribution of the total interference. For both situations, we derive the distribution of signal-to-interference ratio (SIR), coverage probability, ergodic capacity, and SERs for the DBPSK and BPSK. We study how these measures are affected by the number of hops. The accuracy of the analytical results is verified via Monte-Carlo simulation. We show that multi-hop relaying provides significant coverage improvements in blockage-prone mmWave networks.

Statistical Analysis of FSO Links Employing Multiple Transmitter/Receiver Strategy over Double-Generalized and Gamma–Gamma Fading Channel Using Different Modulation Techniques

AbstractFree space optical (FSO) communication links have recently received lot of attention as high bandwidth and cost-effective access technique. However, the transmission medium, i. e. atmosphere, itself is a major spoilsport factor as atmospheric turbulence may lead to fading. The legacy of spatial diversity techniques which have already proven their worth as effective mechanism to counter channel fading in radio links has also been extended to FSO links in this paper. A mathematical model to evaluate error rate performance of FSO links over strong turbulent conditions using gamma–gamma and double-generalized gamma channel model for different modulation techniques has also been included. It was observed that higher modulation techniques such as binary phase shift keying (BPSK) and differential phase shift keying (DPSK) allow superior error performance as compared to on–off keying (OOK) links, and this performance further enhances with incorporation of spatial diversity techniques. However, across different diversity options, explained in this paper, BPSK–MISO links were the best choice for turbulent conditions.

Differential phase-shift keying heterodyne coherent detection with local oscillation enhancement

In the field of intersatellite laser communication, there are two high-sensitivity demodulation methods: binary phase-shift keying (BPSK) coherent detection and differential phase-shift keying (DPSK) coherent detection. After taking into account the advantages and disadvantages of BPSK and DPSK, a DPSK heterodyne coherent detection scheme with local oscillation enhancement is proposed. The structure and the principles of this detection system are described, and the theoretical deduction is presented. Moreover, an experimental setup was constructed to test the proposed detection scheme. The offline processing procedure and results are presented. This scheme has potential applications in high-speed intersatellite laser communication.

Analyzing selective relaying for multiple‐relay–based differential DF‐FSO network with pointing errors

AbstractIn this paper, we examine differential modulation for the decode‐and‐forward(DF) based cooperative free‐space optical (FSO) network. We consider multiple relays for transmitting differential binary phase‐shift keying (DBPSK) data from an optical source to destination along with a direct path between the two. The relays utilize the selective relaying protocol where the source data is forwarded to the destination only in the case of error‐free decoding by the relays. We derive the unified expression of probability density function (PDF) of the signal‐to‐noise ratio (SNR) for generalized‐ ( ) distribution with pointing error (PE) considering both intensity modulation/direct detection (IM/DD) and heterodyne detection techniques. The derived unified PDF of SNR for distribution is mathematically combined with the unified PDF of SNR for the Gamma‐Gamma (GG) distribution. This combining enables us to obtain a single closed‐form expression for a particular performance metric, which is applicable to both and GG distributions with PE and both IM/DD and heterodyne detection techniques. More specifically, we derive the average bit error rate (ABER) and outage probability(OP) for the considered multiple‐relay–based DF‐FSO network. Furthermore, we analyze the asymptotic BER and asymptotic outage performances for the considered system at high SNR of source to relay links and obtain the diversity order, analytically. The impact of different power allocation schemes on ABER and OP is determined by utilizing the power allocation factor. The derived results clearly demonstrate the impact of severe atmospheric conditions, PE, the type of detection scheme, and the number of relays on the network performance. All the derived analytical results are verified through simulations.