Bi-phase Shift Keying Research Articles

Low Density Parity Check Codes Constructed from Hankel Matrices

In this paper, a new technique for constructing low density parity check codes based on the Hankel matrix and circulant permutation matrices is proposed. The new codes are exempt of any cycle of length 4. To ensure that parity check bits can be recursively calculated with linear computational complexity, a dual-diagonal structure is applied to the parity check matrices of those codes. The proposed codes provide a very low encoding complexity and reduce the stored memory of the matrix H in which this matrix can be easily implemented comparing to others codes used in channel coding. The new LDPC codes are compared, by simulation, with uncoded bi-phase shift keying (BPSK). The result shows that the proposed codes perform very well over additive white Gaussian noise (AWGN) channels.

Analysis and Implementation of a Gaussian Addition IR-UWB Transmitter for Increased Spectral Efficiency

This paper describes a technique to improve the spectral efficiency and increase the energy in the transmitted pulse of an impulse-radio, ultra-wideband (IR-UWB) transmitter utilizing bi-phase shift keying (BPSK) modulation and working in the frequency range of 3.1–10.6 GHz. Two Gaussian bi-phase pulses are produced and form the base-band signal. These two signals are delayed with respect to each other and are independently up-converted to a different region of the UWB spectrum. The two up-converted signals are then combined to form the final IR-UWB BPSK output signal. The IR-UWB output signal is analyzed in both the time domain and frequency domain to determine time-bandwidth product and spectral efficiency ( $$\eta $$ ). By combining the two up-converted gaussian signals, the spectral efficiency is increased to 77% and the time-bandwidth product of the output signal is 1.7. For a transmitter operating at a data rate of 250 Mbps, the energy per pulse of the output signal can be increased to 4.33 pJ while staying within the FCC spectral and power limits. This technique can also be used to produce a −30 dB notch at 5.9 GHz to further reduce any interference from an IEEE 802.11p Wifi signal.

A 250-Mb/s Data Rate IR-UWB Transmitter Using Current-Reused Technique

This paper describes the design, simulation, implementation and testing of an impulse-radio ultra-wideband bi-phase shift keying (IR-UWB BPSK) transmitter, working in the frequency range between 3.5 and 6.5 GHz. The transmitter has been optimized to achieve the maximum distance of transmission while working within the power limits specified by the Federal Communications Commission (FCC). In this transmitter, the IR-UWB signal is generated by differentiating a Gaussian signal and then amplifying the differentiated signal. This is accomplished using a current-reused power amplifier circuit as both the differentiator and amplifier. A theoretical analysis is performed to obtain the relationship between the output amplitude and the data rate of the transmitted signal. The simulations and experimental results of the IR-UWB BPSK transmitter, implemented in a 180-nm CMOS process, are then presented. The transmitter was found to function at data rates up to 250 Mb/s with a maximum peak amplitude of 0.5 V. The dc energy consumption of the transmitter is 86 pJ/pulse. The energy efficiency is 26.2% for the pulsewidth of 1 ns. The experimental results show that power spectral density of the transmitter agrees with the simulated results and is within the FCC limits. The total core area of the chip is 0.22 mm2.

An Estimation Method for number of carrier frequency

This paper proposes a method that utilizes AR model power spectrum estimation based on Burg algorithm to estimate the number of carrier frequency in single pulse. In the modern electronic and information warfare, the pulse signal form of radar is complex and changeable, among which single pulse with multi-carrier frequencies is the most typical one, such as the frequency shift keying (FSK) signal, the frequency shift keying with linear frequency (FSK-LFM) hybrid modulation signal and the frequency shift keying with bi-phase shift keying (FSK-BPSK) hybrid modulation signal. In view of this kind of single pulse which has multi-carrier fre- quencies, this paper adopts a method which transforms the complex signal into AR model, then takes power spectrum based on Burg algorithm to show the effect. Experimental results show that the estimation method still can determine the number of carrier frequencies accurately even when the signal noise ratio (SNR) is very low.

방향 탐지용 전파형 대공 근접 신관센서

This paper presents the direction finding proximity fuze sensor using the clutter rejection method and the adaptive target detection algorithm for anti-air missiles. To remove effects by clutter and detect a target accurately, the clutter rejection method of Legendre sequence with BPSK(Bi phase Shift Keying) modulation has been proposed and the Doppler signal which has cross correlation characteristics is obtained from reflected target signals. Considering the change of the Doppler signal, the adaptive target detection algorithm has been developed and the direction finding algorithm has been fulfilled by comparing received powers from adjacent three receiving antennas. The encounter simulation test apparatus was made to collect and analyze reflected signal and test results showed that the -10 dBsm target was detected over 10 meters and the target with mesh clutter was detected and direction was distinguished definitely.Keywords : BPSK, Cross-Correlation(교차상관), Range Gate(거리 창), Clutter Rejection(클러터 제거), Direction Finding Fuze(방향구분 신관)

방향 탐지용 대공 근접 신관센서의 BPSK 송수신기 설계에 관한 연구

This paper describes the fundamentals, design, realization and test results of a BPSK(Bi Phase Shift Keying) transceiver for the direction finding proximity fuze sensor for anti-aircrafts or air missiles. The BPSK transceiver for the direction finding fuze sensor has been designed to detect a moving target by Doppler signal processing with the code correlation method and to distinguish direction by comparing received powers of each Doppler signal from adjacent three receiving antennas. The electrical and ESS(Environmental Stress Screening) tests of the BPSK transceiver showed satisfactory results and target detection and direction finding performances proved to be successful through dynamic operation tests by 155 mm gun firing.

Baseband Signals and Power in Load-Modulated Digital Backscatter

Passive digital backscatter signals in systems like radio frequency identification (RFID) are usually received along with strong interference from a leaked carrier. The simplest way to quantify the “useful” communication signal is to separate it as an amplitude-shift keying (ASK) or biphase-shift keying (BPSK) component. These definitions give different power normalizations, posing some complexity in comparison of link quantities. This letter investigates their suitability in terms of basic signal theory and conservation of energy to clarify relationships between the baseband signals and “backscattered power.” Defining received backscatter as BPSK guarantees energy conservation for arbitrary tag modulation loads.

A compact low power ultra wideband impulse generator on 0.18 μM CMOS technology

This article presents a compact ultra wideband (UWB) impulse generator (IG) with special shaping circuit that can operate intermittently.The pulse last for 4 ns and the measured −10 dB bandwidth is about 460 MHz. The UWB IG employs biphase shift keying (BPSK) scrambling and the power consumption is 7.3 mW at a repetition frequency of 125 Mbps. It was fabricated using Taiwan Semi-conductor Manufacture Company (TSMC) 0.18 μm CMOS process. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1128–1131, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25890

A 1 Gb/s 3.8 pJ/bit Differential Input BPSK Detection Scheme for UWB-IR Communication Using 180 nm CMOS Technology

A CMOS detection procedure for ultra-wideband impulse radio (UWB-IR) communication system, employing Bi-Phase Shift Keying (BPSK) modulation scheme, is presented here. The chip was designed and fabricated in a 180nm CMOS process and it requires a supply voltage of 1.8V, with a die area of 0.01mm2. A train of Gaussian Monocycle Pulses (GMP), modulated by a random data sequence of 1Gb/s, has been detected successfully by the detector. Ability to process differential data without using conventional blocks like mixer, correlator etc. while consuming a very low power (3.8pJ/bit for a data rate of 1Gb/s) is the novelty of this work. The detection scheme employing a simple architecture with a noncoherent detection mechanism is well suited for UWB-IR communication system.

A 800 Mb/s CMOS detection scheme for UWB impulse-radio communication

A CMOS detection procedure for ultra-wideband impulse radio (UWB-IR) communication system, employing Bi-Phase Shift Keying (BPSK) modulation scheme, is presented here. The chip, designed and fabricated in a 0.18 μ m CMOS process, requires a supply voltage of 1.8 V and occupies a die area of 0.01 mm 2. A train of Gaussian monocycle pulses (GMP), modulated by a random data sequence of 800 Mb/s, is detected successfully by the detector. The detection scheme employing a very simple architecture with a power consumption of 3 mW is well suited for non-coherent wireless communication system.

Fully integrated CMOS impulse UWB transmitter front-ends with BPSK modulation

New fully integrated single-chip impulse ultra-wideband (UWB) transmitter front-ends, integrating tunable impulse or monocycle pulse generator with bi-phase shift keying (BPSK) modulator, has been developed using a standard low-cost 0.18-μm CMOS process. The monocycle pulse generator component produces 0.7–0.75 V peak-to-peak monocycle pulse with 140–350 ps tunable pulse duration. The impulse generator generates 0.95–1.05 V peak-to-peak Gaussian-type impulse signal with 100–300 ps tunable pulse duration. The BPSK modulator controls the pulse generator to generate positive or negative pulse signal depending on the “1” or “0” digital data information. The pulse signals produced by the developed transmitters are useful for various UWB applications, especially those requiring the capability of changing ranges and resolutions using only a single system. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1609–1614, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.25250

Acoustic Communication in Air Using Differential Biphase Shift Keying with Influence of Impulse Response and Background Noise

We describe short-range acoustic communication in air using differential biphase shift keying (DBPSK). In this system, a carrier recovery circuit is unnecessary, since the differential encoding is adopted, and the system configuration is simple. The acoustic transmission channel can be simply constructed of only a loudspeaker (SP) and a microphone (MIC). Acoustic communication in air has three problems that degrade the quality of communication. There are multipath fading by reflected waves, the influence of the impulse response of the SP and MIC and that of background noise. Even when multipath fading is disregarded, the performance is limited by the influence of the impulse response of the SP and MIC and that of the background noise. In this study, the performance limits are experimentally evaluated, and the design guidelines for the one-symbol time and signal-to-noise ratio are obtained for an acoustic DBPSK system. The period of a particularly intense influence of the impulse response of the acoustic system is 0.3 ms or more. If the one-symbol time is set at 0.8 ms, the communication quality becomes stable.

Ultra-wideband SAW correlator

A surface acoustic wave (SAW) correlator that satisfies FCC bandwidth requirements for ultra-wideband (UWB) operation has been built and tested. The correlator operates within the 3.1 to 10.6 GHz bandwidth region and uses bi-phase shift keying (BPSK) modulation to achieve a spreading of the main lobe to a 25% bandwidth. This device is capable of spreading or de-spreading a UWB signal directly to or from base-band to microwave frequencies.

Acousto-optic system for automatic identification and decoding of digitally modulated signals

University of PlymouthSchool of Electronic Communication andElectrical EngineeringDrake CircusPlymouth, PL4 8AAUnited KingdomE-mail: creeve@plymouth.ac.ukAbstract. A simple acousto-optic system is described that is capable ofdemodulating frequency- and phase-modulated signals using a bicellphotodetector. A summary of an analytical study of the system is pro-vided, describing its main performance characteristics. Results from aMathcad model of the system are presented showing that, by taking thesum and difference of the outputs from the two bicell elements, it ispossible to identify and demodulate a wide range of different types ofmodulation without any a prioriinformation. Thus the technique is wellsuited for surveillance receiver and electronic support measures (ESM)applications. In particular, it is shown that biphase shift keying (BPSK),quaternary phase shift keying (QPSK), offset-keyed QPSK, differentialQPSK, continuous phase frequency shift keying (FSK) [including mini-mum shift keying (MSK)], and ordinary FSK all give unique and easilyidentifiable signatures. Experimental results are presented, which are ingood agreement with both theoretical and modeled results.

Precision waveform shaping and precompensation for high data rate space communications systems

This paper studies a memory-based pulse shaping and traveling wave tube precompensation technique applied to high data rate satellite communications. Baseband I and Q waveforms are synthesized from data stored in a distributed arithmetic architecture. The waveforms are adjusted to minimize intersymbol interference spectral bandwidth and traveling wave tube distortion. We evaluate its performance in a simulated bi-phase shift keying (BPSK) link. The results show that memory-based precompensation has great potential to improve link performance.

Amplification of a bi-phase shift-key modulated signal by a mm-wave FEL

Abstract Bi-phase shift keying (BPSK) is a modulation scheme used in communications and radar in which the phase of a transmitted rf signal is switched in a coded pattern between discrete values differing by π radians. The transmitted information rate (in communications) or resolution (in imaging radar) depends on the rate at which the transmitted signal can be modulated. Modulation rates of greater than 1 GHz are generally desired. Although the instantaneous gain bandwidth of a mm-wave FEL amplifier can be much greater than 10 GHz, slippage may limit the BPSK modulation rate that can be amplified. Qualitative slippage arguments would limit the modulation rate to relatively low values; nevertheless, simulations with a time-dependent FEL code (GINGER) indicate that rates of 2 GHz or more are amplified without much loss in modulation integrity. In this paper we describe the effects of slippage in the simulations and discuss the limits of simple slippage arguments.