Binary Frequency Shift Keying Modulation Research Articles

Experimental Demonstration of a Visible Light Communications System Based on Binary Frequency-Shift Keying Modulation: A New Step toward Improved Noise Resilience.

Visible light communications (VLC) are an emerging technology that is increasingly demonstrating its ability to provide wireless communications in areas where radio frequency (RF) technology might have some limitations. Therefore, VLC systems offer possible answers to various applications in outdoor conditions, such as in the road traffic safety domain, or even inside large buildings, such as in indoor positioning applications for blind people. Nevertheless, several challenges must still be addressed in order to obtain a fully reliable solution. One of the most important challenges is focused on further improving the immunity to optical noise. Different from most works, where on-off keying (OOK) modulation and Manchester coding have been the preferred choices, this article proposes a prototype based on a binary frequency-shift keying (BFSK) modulation and non-return-to-zero (NRZ) coding, for which the resilience to noise is compared to that of a standard OOK VLC system. The experimental results showed an optical noise resilience improvement of 25% in direct exposure to incandescent light sources. The VLC system using BFSK modulation was able to maintain a maximum noise irradiance of 3500 µW/cm2 as compared with 2800 µW/cm2 for the OOK modulation, and an improvement of almost 20% in indirect exposure to the incandescent light sources. The VLC system with BFSK modulation was able to maintain the active link in an equivalent maximum noise irradiance of 65,000 µW/cm2, as opposed to the equivalent 54,000 µW/cm2 for the OOK modulation. Based on these results, one can see that based on a proper system design, VLC systems are able to provide impressive resilience to optical noise.

An OOK and Binary FSK Reconfigurable Dual-Band Noncoherent IR-UWB Receiver Supporting Ternary Signaling

This article presents a multiband low-power and low-complexity impulse radio ultrawideband (IR-UWB) noncoherent receiver. The proposed receiver can be digitally reconfigured in three different modes of operation, including two single-band modes and one concurrent dual-band mode. In the two single-band modes, the proposed envelope detection architecture is capable of receiving and demodulating an on–off keying (OOK) pulse stream at RF center frequencies of 2.8 or 4.8 GHz. In the concurrent dual-band mode, the proposed architecture is able to demodulate binary frequency-shift keying (FSK), in addition to OOK demodulation, at center frequencies of 3 and 5 GHz. The receiver is composed of a reconfigurable low-power differential low noise amplifier (LNA), a fully differential squarer (self-mixer circuit), low-pass filter (LPF), and variable gain baseband (BB) amplifiers. The receiver is fabricated in TSMC 130-nm CMOS process technology. The receiver can operate at up to 150 Mb/s with the ternary signaling that is enabled by the binary FSK modulation combined with the OOK modulation in concurrent dual-band mode. At its maximum gain, the receiver achieves a sensitivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$-$</tex-math> </inline-formula> 72 dBm at a bit error rate (BER) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{-3}$</tex-math> </inline-formula> at a 100-Mb/s data rate. It consumes 11.9 and 13.2 mW from a 1.2-V supply in the single-band modes and concurrent dual-band mode, respectively.

A 27-MHz frequency shift keying wireless system resilient to in-band interference for wireless sensing applications

&lt;span lang="EN-US"&gt;A 27-MHz wireless system with binary frequency shift keying (BFSK) modulation at 400-kHz is reported. The receiver has been designed to handle in-band interference corrupting the BFSK signal with the use of complex filters and amplitude comparison method. The BFSK modulation is carried out with a voltage-controlled oscillator before up-converting with a 27-MHz local oscillator. The bipolar junction transistors (BJT-based) power amplifier with 30% efficiency pumps 220 mW into a spiral antenna. The inductive-degenerated low-noise amplifier with a voltage of more than 30 dB amplifies an incoming signal before feeding into a mixer for complex direct down conversion. With deliberate Gaussian interference injection, the minimum ratios between the signal with interference and the interference only at the distance of 2.5, 10 and 15 m are 3.3, 8.5 and 11.5 dB, respectively at a maximum data rate of 20 kbps. Without any interference included, the system can achieve a data rate of 40 kbps at the maximum transmission distance of 15 m. Conceptually agreed with the presented bit-error-rate (BER) analysis, the BER measurements with Gaussian and single-tone/two-tone in-band interferences also confirm superiority offered by the amplitude comparison method where the signal-to-noise ratio is at 1 dB for BER=10&lt;sup&gt;-3&lt;/sup&gt; at 10 kbps (10 dB better than the phase detection counterpart).&lt;/span&gt;

Improvement of Binary Frequency Shift Keying Modulation Performance

M-ary frequency shift keying (FSK) is a low-power, low-data-rate modulation scheme currently used by manufacturers of data transmission equipment. Inter symbol interference (ISI) occurs in all communication systems. To analyze the effect of the raised cosine filter and adaptive equalizer on reducing the ISI, the binary FSK (BFSK) modulation technique has been studied extensively in this research. In this study, we have selected the square root raised cosine filter and the sign least mean square (LMS) equalizer. The bit error rate (BER) performance of the 2-FSK system with the additive white Gaussian noise (AWGN) channel is evaluated and analyzed with the help of Simulink. The best BER value of 1.7e-03 was obtained in this study.

Electric-field assisted spin torque nano-oscillator and binary frequency shift keying modulation

Electric-controlled magnetization precession introduces technologically relevant possibility for developing spin torque nano-oscillators (STNO) with potential applications in microwave emission. Using the perpendicularly magnetized magnetic tunnel junction (MTJ), we show that the magnetization oscillation frequency can be tuned by the co-action of electric field and spin polarized current. The dynamical phase diagram of MTJ-based STNO is analytically predicted through coordinate transformation from the laboratory frame to the rotation frame, by which the nonstationary out-of-plane magnetization precession process is therefore transformed into the stationary process in the rotation frame. Furthermore, using this STNO as a microwave source, we numerically demonstrate that the bit signal can be transmitted by a binary frequency shift keying (BFSK) modulation technique. The BFSK scheme shows good modulation features with no transient state.

Reliability Oriented Modeling and Analysis of Vehicular Power Line Communication for Vehicle to Grid (V2G) Information Exchange System

With the development of new energy technology, more and more plug-in electric vehicles (PEVs) have appeared in our lives. In vehicle to grid (V2G) information exchange, the method that PEVs use to access the grid for information and vehicular data collection is the key factor that affects the reliability and real-time nature of V2G communication. Vehicular power line communication (VPLC) reuses vehicular power cables as a communication medium, which avoids the need for an additional vehicular communication line and optimizes the in-vehicle space. VPLC is being considered as a more competitive solution to reduce the complexity of design, weight, and cost associated with the rapid growth of electronic devices installed in vehicles, especially for PEVs. Nevertheless, there are factors that impact VPLC in such a way that disrupts reliability and introduces problems. One of these challenges is VPLC channel noise, which can reduce communication reliability. Hence, in this paper, we introduce a V2G information interaction system structure, based on power line communication, to establish a VPLC channel model for the vehicular data collection system. The model is developed in Simulink and leverages various vehicular noise models and binary frequency shift keying (BFSK) modulation; it also analyzes the channel characteristics by examining different types of noise based on BFSK. Our simulation results demonstrate the feasibility of PLC under BFSK modulation and demodulation, often used in PEVs, which could provide guidance to the implementation of VPLC in support of practical engineering.

A low power consumption CMOS differential-ring VCO for a wireless sensor

This paper describes a new three-stage voltage controlled ring oscillator (VCO) based on 0.35 μm standard CMOS technology. The VCO was designed for a transmitter operating in the 863–870 MHz European band for wireless sensor applications. The transmitter is designed for binary frequency-shift keying (BFSK) modulation, communicating a maximum data rate of 20 kb/s. In addition to the VCO, the transmitter combines a BFSK modulator, an up conversion mixer, a power amplifier and an 863–870 MHz band pass filter. The modulator uses the frequency hopping spread spectrum and it is intended for short range wireless applications, such as wireless sensor networks. The oscillation frequency of the VCO is controlled by a voltage VCTRL. Simulation results of the fully differential VCO with positive feedback show that the estimated power consumption, at desired oscillation frequency and under a supply voltage of 3.3 V, is only 7.48 mW. The proposed VCO exhibits a phase noise lower than −126 dBc/Hz at 10 MHz offset frequency.

FPGA Implementation of BASK-BFSK-BPSK Digital Modulators [Testing Ourselves

Field-programmable gate-array (FPGA) implementations of binary amplitude-shift keying (BASK), binary frequency-shift keying (BFSK), and binary phase-shift keying (BPSK) digital modulators are presented. The proposed designs are aimed at educational purposes in a digital communication course. They employ the minimum number of blocks necessary for achieving BASK, BFSK, and BPSK modulation, and for full integration with the other functional parts of the Altera Development and Education (DE2) FPGA board. The input carrier signal and the bit stream (modulating signal) are user controllable. These digital modulators were developed and compiled to a Verilog Hardware Description Language (HDL) netlist, and were later implemented into an Altera DE2 FPGA board. The functionality of these digital modulators was demonstrated through simulations using the Quartus II simulation software, and experimental measurements of the real-time modulated signal via an oscilloscope.

A ZCZ‐CDMA system with BFSK modulation

SUMMARYA quasi‐timing synchronous code division multiple access (CDMA) system called ZCZ‐CDMA, which uses a set of sequences with a zero‐correlation zone called ZCZ code as a spreading code, is useful for short‐range wireless communications because of its excellent properties such as co‐channel interference‐free performance, simplified hardware design, and low transmit power as well as fast frame synchronization capability. In this paper, a ZCZ‐CDMA system with binary frequency‐shift keying (BFSK) modulation called BFSK‐ZCZ‐CDMA is proposed. This system is characterized by using a pair of balanced ZCZ codes for spreading and transmitting the two spread components over the respective keying carrier frequencies. Its bit error rate performance, compared with those of existing BPSK‐ZCZ‐CDMA, ASK‐ZCZ‐CDMA, and CDMA systems using the other spreading codes, is evaluated in theory and simulation. The bit error rate performance of the three ZCZ‐CDMA systems over additive white Gaussian noise and Rayleigh fading channels are formulated. It is proved that BFSK‐ZCZ‐CDMA is much more robust in anti‐fading performance and low transmit power in such an environment that fading distributions on the keying frequencies are independent mutually. Fading versus frequency characteristics are also investigated. Copyright © 2012 John Wiley &amp; Sons, Ltd.

An 863–870 MHz spread-spectrum FSK transceiver design for wireless sensor

Simulation results of a 863–870 MHz frequency-hopped spread-spectrum (FHSS) transceiver with binary frequency shift keying (BFSK) modulation at 20 kb/s for wireless sensor applications is presented. The transmit/receive RF front end contains a BFSK modulator, an upconversion mixer, a power amplifier (PA), and an 863–870 MHz band pass filter (BPF) at the transmitter side and a low-noise amplifier with down conversion mixer to zero-IF, a low-pass channel-select filter, a limiter and a BFSK demodulator at the receiver side. The various block parameters of the transmit/receive RF front end like noise figure (NF), gain, 1 dB compression point (P-1 dB), and IIP3 are simulated and optimized to meet low power and low cost transceiver specifications. The transmitter simulations show an output ACPR (adjacent channel power ratio) of −22 dBc, 3.3 dBm P-1 dB of PA, and transmitted power of 0 dBm. The receiver simulations show 51.1 dB conversion gain, −7 dBm IIP3, −15 dB return loss (S11), and 10 dB NF. Low power arctangent-differentiated BFSK demodulator has been chosen and the BER performance has been co simulated with the analog receiver. The complete receiver achieves a BER of 10 −3 at 10.5 dB of EbtoNo. The transceiver simulations show an RMS frequency error of 1.45 kHz.

Orthogonal frequency division multiplexing with BFSK modulation in frequency selective Rayleigh and Rician fading channels

The performance of noncoherent reception with orthogonal frequency division multiplexing (OFDM) and binary frequency-shift-keying (BFSK) modulation over multipath fading channels with noise is investigated. This analysis demonstrates that it is possible to transmit information in selective channels with no symbol interference. Expressions of the bit error probability (BEP) are derived in the context of frequency selective Rayleigh and frequency selective Rician fading channels with and without convolutional coding. >

Error probability of fast frequency hopping spread spectrum with BFSK modulation in selective Rayleigh and selective Rician fading channels

The performance of noncoherent reception in fast frequency hopped spread-spectrum (FFH-SS) communication systems operating through noisy, fading multipath channels is investigated. Systems operating with binary frequency-shift keying (BFSK) modulation and noncoherent demodulation are examined under the assumption of very slow fading. These analyses demonstrate the frequency hopping benefits in selective channels. Expressions are derived for the bit error rate in the context of selective Rayleigh and selective Rician fading channels, as a function of channel and system parameters. >