A Fully Integrated LDR IR-UWB CMOS Transceiver Based on "1.5-bit" Direct Sampling

This paper addresses Differential Binary Phase Shift Keying (DBPSK) modulation implemented on SDR platform for the development of digital data communications based on SDR. DBPSK modulation performance perceived at Packet Error Rate (PER) is evaluated in terms of Eb/No or S/N ratio, carrier frequency, bit rate, gain, roll-off factor of root Nyquist filter or root raised cosine filter, and of size of payload from delivered data. Based on this results, the smallest PER could be obtained by setting Eb/No value which is greater than 13 dB, carrier frequency of at least 0,3 MHz, optimum bit rate of 256 kbps, optimum range payload size of 2000 up to 4000 bytes, and roll-off factor of Nyquist or root-raised cosine filter of 0.1<alfa<0.9.

Wireless data transmission with binary phase-shift keying modulation encoded on a 92 GHz carrier is achieved using photonic components. A high-speed photodiode is used to convert the doubly-modulated optical signal to a modulated millimeter-wave carrier. A W-band Mach-Zehnder interferometer with a one-bit time delay is used to directly detect the differential phase-shift keyed millimeter-wave wireless signal without the use of a local oscillator. Field tests with antennas separated by 890 m demonstrate the ability to discriminate two phase states for differential binary phase shift keying (DBPSK) and four phase states for differential quadrature phase shift keying (DQPSK) at data rates of 2.3 Gb/s and 4.6 Gb/s, respectively.

Power line communication (PLC) utilizes power lines for the purpose of electronic data transmission. Differential binary phase shift keying (DBPSK) is a popular modulation scheme proposed in the PLC standards like G3, PRIME, and IEEE P1901.2. This letter provides the performance evaluation of a PLC system assuming DBPSK modulation under the combined effect of Nakagami- $m$ background noise and impulsive noise. We utilize a simple, yet accurate approximation available in literature to derive the probability density function of the sum of two Nakagami- $m$ random variables. Closed-form expressions of the analytical average bit error rate and the outage probability of the system are derived. Validity of the derived analytical expressions is closely verified by simulated results.

This paper presents recent progress toward the realization of ultrahigh-speed coherent optical transmission with a single-channel bit rate of more than 1 Tbit/s using ultrashort pulse technology and an advanced modulation format. We first describe Tbit/s optical time-division multiplexing (OTDM) transmission employing differential binary or quadrature phase shift keying. We present our recent demonstrations of single-polarization 640-Gb/s differential phase-shift keying and 1.28-Tb/s differential quadrature phase-shift keying transmissions over 525 km, which employ an ultrafast optical Fourier transformation technique. We then focus on coherent optical transmission using quadrature amplitude modulation (QAM) with a multiplicity of 512 that enables us to achieve an ultrahigh spectral efficiency of more than 10 b/s/Hz. Finally, we demonstrate a novel ultrahigh-speed, spectrally efficient coherent pulse transmission combining OTDM and QAM. A 400 Gb/s, 32 RZ/QAM signal was successfully transmitted over 225 km on a single carrier at 10 Gsymbol/s × 4-OTDM.

A multi-tone code division multiple access (MT-CDMA) system with post-detection diversity combining is analyzed. The analysis is presented in terms of average bit error rate (BER). The modulator uses differential quadrature phase shift keying (DQPSK) signaling over a slowly Rician fading and frequency selective channel in the indoor environment. Here, the influence of the order of diversity and number of tones is studied for given bandwidth (BW), bit rate and transmitter power. The paper also compares the BER performance between differential binary phase shift keying (DBPSK) and DQPSK based MT-CDMA systems.

Performance Analysis of Different Phase Shift Keying Modulation Schemes in Aeronautical Channels

In Industry 4.0 and Agriculture 4.0, there are logistics areas where robots can play an important role, for example by following a person at a certain distance. These robots can transport heavy tools or simply help collect certain items, such as harvested fruits. The use of Ultra Wide Band (UWB) transceivers as range sensors is becoming very common in the field of robotics, i.e. for localising goods and machines. Since UWB technology has very accurate time resolution, it is advantageous for techniques such as Time Of Arrival (TOA), which can estimate distance by measuring the time between message frames. In this work, UWB transceivers are used as range sensors to track pedestrians/operators. In this work we propose the use of two algorithms for relative localization, between a person and robot. Both algorithms use a similar 2-dimensional occupancy grid, but differ in filtering. The first is based on a Extended Kalman Filter (EKF) that fuses the range sensor with odometry. The second is based on an Histogram Filter that calculates the pedestrian position by discretizing the state space in well-defined regions. Finally, a controller is implemented to autonomously command the robot. Both approaches are tested and compared on a real differential drive robot. Both proposed solutions are able to follow a pedestrian at speeds of 0.1 m/s, and are promising solutions to complement other solutions based on cameras and LiDAR.

A field programmable gate array (FPGA)-based physical layer phase-encryption technique suitable for applications in high-speed passive optical networks is presented. The physical layer ciphering technique is based on a combination of multilevel phase shift keying (PSK) modulation and binary differential PSK. A mathematical model of the system is first derived and numerical simulations are obtained using Mathematica. Expressions for the probability of error for both a legitimate and eavesdropping receiver are derived and evaluated numerically. The results from experimental implementation using high-speed phase modulators and FPGAs are also given to further prove the efficacy of the presented technique. The macroscopic cryptography technique offers completely opaque communication over trans-oceanic distances, gigabit date rates and multiple wavelengths.

This paper presents a comparative study of the use of two modulation techniques for a fast frequency hopping (FFH) spread spectrum system for wireless communication over a non-selective Rayleigh fading channel. The modulation techniques considered are binary frequency shift keying (BFSK) and differential phase shift keying (DPSK). The comparison standard chosen is that of the signal-to-noise ratio (SNR) for achieving a given bit error rate (BER). It is found that DPSK is capable of giving a gain of about 3 dB over BFSK indicating the potential for employing DPSK for such a spread spectrum. A square law combiner for the case of DPSK has also been suggested.

The primary characteristic of the ultra-wideband (UWB) indoor radio channel is the large frequency diversity, which translates into a large number of resolvable paths and, consequently, in a low signal energy-per-path. Code acquisition is particularly difficult in such a hostile environment if the available diversity is not exploited. This paper deals with the initial code acquisition for an UWB impulse radio (IR) system in a dense multipath environment. In particular, we propose an approach based upon a non-coherent Rake detector (NCRD), which combines the energy collected from different paths in a non-coherent fashion. System performance of the NCRD is analyzed in multipath fading channels, showing that satisfactory performance is achievable with relatively low complexity.

This work presents a binary differential phase-shift keying (DPSK) modulation technique for visible light communication (VLC) systems aimed at low to moderate data rate applications. VLC uses the modulated light of LEDs to transmit data wireless. Such feature is added into artificial lighting systems by controlling the light intensity of a source. However, in most cases, modulation capabilities for VLC are employed with the addition of extra power components, which may harm efficiency and cost standards. Therefore, single switch LED drivers are preferable to provide VLC along with average current regulation. They are standard low-cost solutions that are able to perform both functions providing a satisfactory efficiency. Hence, in this work, DPSK modulation is applied to a buck converter operating in continuous conduction mode at 250 kHz, providing a raw data rate of 125 kbps. DPSK is advantageous because it overcomes possible parameters changes at the converter, along with possible duty cycle changes given by the control system of the average current for lighting. Moreover, the system performance is evaluated by means of its bit error ratio (BER) over signal-to-noise ratio (SNR), in a line-of-sight setup with variable distances between transmitter and receiver, showing a good behaviour of a BER less than 10−3 for about 8.1 $m$ in a 8.4 W LED load.

We propose an iterative decoding scheme for low density parity check codes concatenated with binary differential phase shift keying (BDPSK) in additive white Gaussian channels with unknown phase offset by viewing the BDPSK modulator as the encoder of a rate-one convolutional code. To assist this iterative scheme, a new log-likelihood ratio (LLR) metric based on three consecutive received symbols is derived. This metric takes a priori information of other coded bits into account and therefore applicable to the proposed iterative scheme. We show that the proposed iterative scheme has better performance than systems using other LLR metrics for noncoherent detections. The performance of the proposed scheme under signal-to-noise ratio estimation error is also investigated.

In the present work, simple closed-form series solutions for the average error rate of several coherent modulation schemes such as, binary phase shift keying (BPSK), binary frequency shift keying (BFSK), differential binary phase shift keying (DBPSK), quadrature phase shift keying (QPSK), offset-QPSK, minimum shift keying (MSK), and square M-ary quadrature amplitude modulation (M-QAM), operating over frequency non-selective slow Rician fading channel and corrupted by additive white Gaussian noise (AWGN) are derived. Further, to improve the link quality, receiver antenna space diversity is considered, where multiple independent and identically distributed (i.i.d.) as well as uncorrelated signal replicas are combined before successive demodulation. The proposed linear predetection combiner follows optimum maximal ratio combining (MRC) algorithm. Starting from a novel unified expression of conditional error probability the error rates are analysed using probability density function (pdf) based approach. The derived end expressions, consisting of rapidly converging infinite series summations of Gauss hypergeometric function, are accurate, free from any numerical integration and general enough, as it encompasses as special situations, some cases of non-diversity, non-fading AWGN and Rayleigh fading. Symbol or, bit error probabilities (SEP/BEP) are graphically displayed against signal to noise ratio (SNR) per bit per channel for all the digital modulation schemes stated above with different values of diversity order L and varying values of the channel specular-to-scatter ratio or, the Rician parameter K, as found from the measured statistics of mobile and indoor wireless channels. In addition, to examine the dependence of error rate performance of M-QAM on the constellation size M, numerical results are plotted for various values of M. Selected simulation results are also provided to verify the analytical deductions. The series solutions presented in current text realize a trade-off between precision and complexity and offers valuable insight into the performance evaluation over a fading channel in a unified manner.

Cochannel interference effect on BEP performance of SSC receiver in correlated Rician fading

Dynamic drill-string modeling for acoustic telemetry