Transceiver Prototype Research Articles

Структура и элементная база приёмо-передающего модуля для организации подводной оптической беспроводной системы передачи данных

In the paper, the results of theoretical study of a wireless optical data transmission channel, as well as experimental study of its characteristics, taking into account different configurations of the optical component base of receiving and transmitting modules, were presented. The model of the wireless underwater optical communication channel with pulse-position modulation (4 bits per symbol) of digital data traffic with 100 Mbps is proposed. The model showed that to organize a communication channel on a 10 m path, the use of an array of light-emitting diodes (LEDs) is requires (the amount is up to 20 LEDs). For this case, a sufficiently large route budget will be provided, even with additional factor that reduce the efficiency of light propagation in seawater. The LEDs were chosen to organize the data transmission channel, since they have a wide radiation pattern and allow the implementation of a relatively simple driver circuit. The required optical radiation power is realized with the use of an array of LEDs. Schematic diagrams of the LEDs driver and power supply for the receiving and transmitting modules have been designed. A measuring layout with optical transmitter and receiver blocks has been implemented. The test signal is a regular sequence of pulses with a duty cycle of 2, and a frequency of 1 MHz. In the receiving module, the signal from the output of the pin photodiode is amplified using a wideband operational amplifier. Sets of 3 pin photodiodes and 10 LEDs were selected and tests were carried out to determine options for optical components that provide the best time characteristics of the output electrical signal in terms of delay time, rising and falling edges of pulses in a wireless optical airborne communication channel. Also, measurements were done on an air path with a length of 0.25-3 m using one or two LEDs as part of the transmitting module. It has been experimentally confirmed that the organization of a communication channel with a length of up to 10 m requires about 15-20 light-emitting diodes. Further study involves the designing and testing of a driver for the LEDs array and a prototype transceiver module.

An 8b9b 77.44-Gb/s Noise-Immune Spatial-Delta Coded Transceiver for Short-Reach Memory Interfaces in 28-nm CMOS

A noise-immune spatial-delta coding (SDC) scheme is proposed for single-ended multi-lane links. The SDC technique allows differential sensing of single-ended PAM2 signals for high signal integrity while still achieving the same pin efficiency as the 8b9b data bus (DBI) scheme, providing high compatibility with conventional DDR interfaces. The SDC encoding/decoding functions are implemented with simple XOR gates to minimize power and latency overhead. Continuous-time linear equalizers in the receiver compensate for distortions in incoming pseudodifferential signals with high tolerance on dynamic common-mode switching associated with the SDC operation. An 8b9b SDC transceiver prototype array composed of nine data channels and a differential clock channel has been fabricated in 28-nm CMOS technology for demonstration. The transceiver array achieves a 77.44 Gb/s aggregate data rate with 9 wires at 9.68 Gbaud/s. The bit error rate is measured to be less than 1e-12 while consuming 4.9 pJ/b from a 1.25-V supply.

Design and analysis of microstrip transceiver array antennas with the function to suppress beam deflection for 77 GHz automotive radar

A microstrip transceiver array antenna with high beam pointing accuracy is designed for automotive radar. Considering the influence of the lossy conductor on the excitation current, the beam deflection problem formed by the passive microstrip series-feed linear array is analyzed and solved. Compared with the traditional microstrip series-feed linear array, the microstrip series feeder array designed in this paper has good beam pointing accuracy. A power divider based on substrate-integrated waveguide (SIW) and microstrip line (MSL) with Chebyshev amplitude distribution(applied to the transmit array antenna) and binomial amplitude distribution(applied to the receive array antenna), respectively, is designed as the feeding network of the linear array. The fabrication and measurement of the prototype transceiver array antenna are completed to verify its beam directivity. The simulation and measurement results show that the E-plane main beam of the transceiver array antenna radiation pattern has good pointing accuracy, which makes the detection accuracy of the automotive radar significantly improved.

Analysis of a Multiwire, Multilevel, and Symbol Correlation Combination Scheme

The required data rate of wireline communications has increased; however, channel attenuation limits the data bandwidth. Bit-efficient signaling is an effective and efficient solution because more data can be transmitted at the same Nyquist frequency. Several methods for increasing bit efficiency, such as multi-wire signaling, multi-level signaling, and symbol correlation schemes, have been proposed. Each scheme can generate additional codes by encoding the data. Additional codes can be used to transmit more data or to embed data transitions. In this study, the aforementioned schemes are analyzed, and a method is developed to combine them, maximize the bit efficiency, and ensure the data transition density. For the prototype transceiver, a 4-wire PAM-3 (4W3P) signaling scheme was adopted. The 4W3P signaling scheme can increase the bit efficiency to 200% while maintaining the DC-balanced characteristics. Transceiver building blocks, such as the TX driver, feed-forward equalizer, and analog front-end, were optimized for the proposed signaling scheme. The prototype transceiver was fabricated using 28 nm CMOS technology, occupying 0.012 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The RX was measured using the TX and achieved a BER less than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{-12}$ </tex-math></inline-formula> at 40 Gb/s over the four wires, with a total transceiver energy efficiency of 1.52 pJ/bit.

A Broadband MFCW Agile Radar Concept for Vital-Sign Detection Under Various Thoracic Movements

A multiple-frequency continuous-wave (MFCW) agile radar system has the ability to cope with various physiological conditions of a human subject. Following the mathematic model, a favorable carrier frequency for detection is pursued by analyzing the amplitude and composition of the baseband signal. In Experiment-1, a CMOS dual-band transceiver prototype emulate searching a subject from a distance. The frequencies of the dual-band system are 4.26–4.95 GHz and 17.06–19.79 GHz. During the experiment, the respiratory signal could be detected up to 12 m, and the heartbeat signal up to 6 m. Even with a wooden or a brick barrier in the path, the vital-sign detection remained satisfactory. Later, a concurrent MFCW detection is performed in Experiment-2 for more precise analyses. From the concurrent results, the breathing status can be inferred, and by cross-correlating the results after the ensemble empirical mode decomposition (EEMD) and principal component analysis (PCA), the nonlinear effects of respiratory harmonics or intermodulation tones are reduced, resulting in an accurate heart rate extraction. The receiver front-end and the signal source are manufactured using a 180-nm CMOS process, both packaged on an RO4003C printed-circuit board (PCB).

A 4.5 Gb/s/pin transceiver with hybrid inter‐symbol interference and far‐end crosstalk equalization for next‐generation high‐bandwidth memory interface

A 4.5 Gb/s/pin transceiver capable of eliminating the inter-symbol interference (ISI) and far-end crosstalk (FEXT) in a hybrid scheme with low power and small area for next-generation high-bandwidth memory (HBM) interfaces is presented. Built around the combination of two ISI and FEXT equalization topologies, the transmitter (TX) energy efficiently reduces data-dependent jitter (DDJ) and crosstalk-induced jitter (CIJ) by using the compensation signal generated from edge detectors (ED) to ensure the sampling margin. The prototype transceiver, implemented using a 28-nm complementary metal-oxide semiconductor (CMOS) process, operates over a 3-mm mimicked silicon interposer channel with 21.2-dB loss. It achieves a data rate per density of 9 Gb/s/μm at a bit error rate (BER) < 10–12 with 0.23 unit interval (UI) eye width for pseudorandom binary sequence (PRBS)15 data while consuming only 1.46 pJ/bit.

Dual-Band, Two-Layer Millimeter-Wave Transceiver for Hybrid MIMO Systems

This article presents a two-layer low-complexity fully connected (FC) RF/analog weighting multi-input–multi-output (MIMO) transceiver comprising an RF weight layer and an analog–baseband weight layer. The transceiver can serve as a small-scale MIMO system by itself and can serve as the building block in a larger hybrid MIMO system. The architecture mitigates the complexity versus spectral-efficiency tradeoffs of existing MIMO architectures and enables MIMO stream/user scalability, superior energy efficiency, and spatial-processing flexibility. A compact, reconfigurable bidirectional circuit architecture is introduced, including a new Cartesian-combining/splitting beamforming receiver/transmitter, dual-band bidirectional beamforming network, dual-band frequency translation chains, and baseband Cartesian beamforming with an improved programmable gain amplifier design. A 28-/37-GHz band, two-layer, eight-element, four-stream hybrid MIMO transceiver prototype is designed in 65-nm CMOS to demonstrate the above features. The prototype achieves accurate beam/null-steering capability, excellent area/power efficiency, and state-of-the-art TX/RX mode performance in two simultaneous bands while demonstrating multi-antenna (up to eight) multi-stream (up to four) over-the-air spatial multiplexing operation using the proposed energy-efficient two-layer hybrid beamforming scheme.

Extending Uplink Coverage of mmWave and Terahertz Systems Through Joint Phase-Time Arrays

In this paper, we establish the potential of joint phase-time arrays (JPTAs) for uplink coverage extension in cellular systems. JPTA allows the base station (BS) to create frequency-dependent wide-beams without sacrificing the array gain. In this work, we propose a novel use case of JPTA where the BS exploits the frequency-dependent beams to serve multiple users&#x2019; equipment (UEs) at different directions simultaneously with the full array gain and with no inter-UE interference. This is achieved by assigning each UE a corresponding bundle of sub-carriers that benefit from the full array-gain. A key feature of this scheme is the prolonged channel access for uplink communication for each user, due to the BS&#x2019;s ability to serve multiple UEs at the same time. We focus on two performance metrics: uplink coverage and uplink throughput. Our results show that using JPTA can extend the uplink coverage range by 3&#x00D7; while boosting the uplink throughput by providing more flexibility for the BS in resource allocation. These results are based on both theoretical analysis and 3GPP spec-compliant simulations with a sub-terahertz transceiver prototype.

A W-Band Single-Antenna FMCW Radar Transceiver With Adaptive Leakage Cancellation

This article presents a leakage cancellation architecture for single-antenna frequency-modulated continuous-wave (FMCW) radars at W-band. A shared antenna for transmitter (TX) and receiver (RX) can substantially reduce the form factor, cost, and complexity of radar modules. Due to the simultaneous operation of the TX and RX in FMCW radars, employing a shared antenna will, however, significantly increase TX-to-RX leakage, resulting in RX saturation and desensitization. Our proposed cancellation scheme employs analog feedback to confine the TX leakage right at the RX input port, and thus, relieves the ongoing RX chain from saturation. The proposed single-antenna transceiver (TRX) prototype was fabricated in 65-nm CMOS technology with a die area of 1 mm2. The output power of 2 dBm was achieved for the TX in a frequency range of 80–84 GHz. In addition, a conversion gain and noise figure of 45 and 15 dB was measured for the RX in the presence of the TX signal via a shared antenna port. TX-to-RX isolation of more than 45 dB was achieved in the operating W-band. The chip consumes 108 mW (80.5 mW for the TX and 27.5 mW for the RX) from a 1.2-V supply voltage. Moreover, the functionality of the single-antenna radar operation was verified by connecting the chip to an on -printed circuit board (PCB) $4 \times 8$ patch antenna array with a simulated gain of 15 dBi, implemented on RO3003 Rogers material. Using the single-antenna radar module as a demo system, a $40\times 50$ cm2 rectangular metallic plate was detected at a distance up to 19 m.

Multibeam Phased-Arrays Using Dual-Vector Distributed Beamforming: Architecture Overview and 28 GHz Transceiver Prototypes

This article presents a dual-vector distributed beamformer architecture that employs a series-feed network and is capable of supporting up to four simultaneous beams. The multibeam array uses scalar functions within each front end to create Cartesian-weighted signals needed for phase shifting. A dual-vector series-feed network combines/distributes these signals for the receiver/transmitter whereas a global quadrature interpolator is used to create two conjugate beams. By using an interpolator on either end of the series feed, a total of four beams can be obtained. Among these four beams, a first beam can be controlled independently, a second beam is formed as an image of the first, a third beam is offset from the first based on the amount of phase shift within the series-feed structure, and a fourth beam is an image of the offset beam. In this work, the theory of operation of the series-feed DVDB is presented and then two different four-element 28 GHz DVDB transceiver array prototypes in 120 nm SiGe BiCMOS technology are described. One uses a hybrid coupler for global interpolation at radio frequency (RF) and the other uses quadrature mixers for global interpolation at baseband. Measurement results for the array employing passive interpolation at RF show excellent phase-shifting performance, including < 1 dB root-mean-squared (RMS) gain error, < 2 degree RMS phase error, 24% 3 dB bandwidth, with 16–18.6 dBm saturated output power in transmit mode and 4.9–7.3 dB noise figure in receive mode. Measurement results for the array employing mixer-based interpolation likewise show excellent phase-shifting performance with similar RMS gain and phase errors and slightly degraded overall RF performance. Comparing the two, we conclude that the DVDB with passive interpolation at RF is better suited for partitioned systems where beamformers and transceivers are realized on separate chips to support larger, scalable arrays. In contrast, the DVDB with mixer-based interpolation is better suited for integrated systems where beamformers and frequency translation functions must be integrated together.

A Hybrid 3D Interconnect With 2x Bandwidth Density Employing Orthogonal Simultaneous Bidirectional Signaling for 3D NoC

For the first time, this work presents a wireless-wireline hybrid 3D interconnect that employs orthogonal simultaneous bidirectional signaling for 3D Network-on-chip to achieve 2x bandwidth density. We combine wireless near-field inductive coupling channel (NFIC) encompassing wireline through-silicon vias (TSV) to leverage orthogonal simultaneous bidirectional (SBD) signaling. This technique provides an efficient way of doubling interconnect bandwidth in the same area by means of passive wireless and wireline interconnects. The proposed hybrid 3D interconnect shows at least -70dB of NFIC-TSV isolation in the band of interest. We also present a comprehensive link analysis to derive the energy-area trade-off of an NFIC link and its fundamental performance limits. Further, we demonstrate on how equalization has the potential to decouple the fundamental energy-area tradeoff. The prototype transceiver measures a simultaneous bidirectional data and clock communication at an effective data rate of 6.6 Gb/s consuming 263 fJ/bit in 65 nm CMOS bulk process. The developed hybrid 3D interconnect architecture exhibits a 2× improved link performance over state-of-the-art 3D simultaneous bidirectional links. A hybrid 3D Network-on-chip (3D NoC) implementation is demonstrated using the proposed hybrid interconnect technology and shows a 50% lower area and cost for the same energy-delay-product (EDP) over the conventional TSV based links.

Weather-limited in-band full-duplex transceiver model for free-space optical communication

Free-space optical (FSO) communication has gained popularity for wireless applications over legacy radio frequency for advantages such as unlicensed operation, spatial reuse, and security. Even though FSO communication can achieve high bit rates, range limitation due to strong attenuation and weather dependency has always restricted its practical applications to controlled settings such as building-to-building communication. Futuristic mobile and secure ad hoc FSO network applications such as smart cars and air-subsea links need more efficient and autonomous link acquisition capabilities, which can be enabled by in-band full-duplex (IBFD) operation. We proposed an IBFD-FSO transceiver prototype consisting of off-the-shelf components to demonstrate the concept of IBFD operation by the isolation technique. We also developed a laser-based IBFD-FSO link model by incorporating an atmospheric attenuation model and self-interference cancellation model. We found that, for clear weather, the maximum achievable link range using commercially available components can be up to 120 m. We also determined weather-dependent performance of the FSO link in terms of visibility and transmit power.

Experimental Tests and Performance Evaluation of a VHF Data Transceiver Prototype for Operation in the Antarctic Regions

Experimental Tests and Performance Evaluation of a VHF Data Transceiver Prototype for Operation in the Antarctic Regions

Characterization of a gigabit transceiver for the ATLAS inner tracker pixel detector readout upgrade

We present a gigabit transceiver prototype Application Specific Integrated Circuit (ASIC), GBCR, for the ATLAS Inner Tracker (ITk) Pixel detector readout upgrade. GBCR is designed in a 65-nm CMOS technology and consists of four upstream receiver channels, a downstream transmitter channel, and an Inter-Integrated Circuit (I2C) slave. The upstream channels receive the data at 5.12 Gbps passing through 5-meter 34-American Wire Gauge (AWG) Twin-axial (Twinax) cables, equalize and retime them with a recovered clock, and then drive an optical transmitter. The downstream channel receives the data at 2.56 Gbps from an optical receiver and drives the cable as same as the upstream channels. The jitter of the upstream channel output is measured to be 35 ps (peak-peak) when the Clock-Data Recovery (CDR) module is turned on and the jitter of the downstream channel output after the cable is 138 ps (peak-peak). The power consumption of each upstream channel is 72 mW when the CDR module is turned on and the downstream channel consumes 27 mW. GBCR survives the total ionizing dose of 200 kGy.

A Body Channel Communication Technique Utilizing Decision Feedback Equalization

This article presents the body channel communication technique that first adopts decision feedback equalisation. For the first time, we characterised post-cursor intersymbol interference of a single-bit pulse response of a human body channel for decision feedback equalisation achieving the first body channel communication faster than 100 Mb/s. In the proposed technique, an 8-tap decision feedback equaliser is utilised at the receiver to compensate for intersymbol interference of the body channel. The experimental results show that the proposed prototype transceiver achieved the highest data rates of 150 Mb/s and 10 Mb/s along 20-cm and about 100-cm body channels, respectively. Compared to the previous best result measured for the same body-channel distance of about 100 cm, the data rate is improved by ten times, showing that the proposed technique can significantly increase the speed of body channel communication.

A 2.56-Gb/s Serial Wireline Transceiver That Supports an Auxiliary Channel in 65-nm CMOS

In this article, an asynchronous serial transceiver that is capable of transmitting and receiving an auxiliary data stream concurrently with the primary data stream is described. The transceiver instantiates the auxiliary data stream by modulating the phase of the primary data without affecting the primary channel transmission and recovery mechanisms. Standard receiver interoperability is maintained since the auxiliary data appear as primary data jitter. Analysis of the proposed transceiver and considerations of the system parameters are included and can be used to determine how such an auxiliary channel is implemented. The proposed transceiver with the auxiliary channel can be widely used in many data communication applications such as for transmitting signatures for authentication or other control information, steganography, or additional data in an existing serial link. A prototype transceiver, implemented in a 65-nm CMOS process, demonstrates the proposed concept with an 80-Mb/s auxiliary channel in a 2.56-Gb/s asynchronous serial link.

Body-Guided Galvanic Coupling Communication for Secure Biometric Data

In a world dominated by the wearable IoT devices, malicious security threats have become a common concern in system design. Guided by this notion, we propose a secure transmission system through body-guided channels using Galvanic Coupling (GC). The GC-method injects weak electrical current into human tissue, primarily propagating through the skin. The proposed design provides impermeability to malicious attacks, (e.g. side-channel sniffing) when sending biometric data, as the body behaves as a natural waveguide. The following contributions are: 1) the analytical formulation and empirical verification of a 3D tissue equivalent circuit model for GC-signal propagation of the human arm-wrist-palm channel; 2) the simulation study of numerous modulation schemes, drawn from the validated results of the GC-channel model; 3) the design and implementation of a transceiver prototype using optimal communication parameters (modulation, frequency, power) for transmission on a dielectrically equivalent tissue phantom; and 4) through the experimental trials, we demonstrate the eavesdropping susceptibility of the GC-signals, and similar body communication techniques, over-the-air and while in direct contact with the medium. The performance results of the GC-transceiver prototype yield a bit error rate of 10−6 with a transmit power of −2 dBm, in addition to over 7 $\times$ reduction of signal radiation outside the body compared to capacitive coupling.

Narrowband hybrid PLC/wireless: Transceiver prototype, hardware resource usage and energy consumption

This work discusses a prototype of the so-called narrowband (NB) hybrid power line communication (PLC)/Wireless transceiver, which jointly uses parallel power line and wireless channels for providing data communication to the Industry 4.0, Smart Grids and the Internet of Things applications. The prototype introduces a modified version of the IEEE 1901.2 Standard, which was designed to fulfill NB - PLC applications, to implement the media access control (MAC) sublayer and the physical (PHY) layer of a hybrid transceiver that is capable of transmitting data through both power line and wireless channels. Therefore, the NB hybrid PLC/Wireless transceiver prototype is compatible with a NB - PLC transceiver that makes use of the IEEE 1901.2 Standard. Moreover, both transceivers can constitute heterogeneous data communication networks that are capable of improving reliability and coverage. Furthermore, based on a field-programmable gate array (FPGA) device, we discuss the hardware resource usage and energy consumption analyses and the hardware feasibility of implementing a bit correction technique at the link layer of the NB hybrid PLC/Wireless transceiver prototype. We show that the signal/data processing block of the proposed transceiver demands only 1.12 times the energy consumption required by a NB - PLC transceiver based on the IEEE 1901.2 Standard. Moreover, the designed roadmap for this kind of hybrid PLC/wireless transceiver demands 1.5 times the hardware resource usage in comparison to the implementation of the PLC transceiver based on the IEEE 1901.2 Standard. Finally, we show that up 5 bits can be corrected at the link layer level without increasing the clock frequency.

Low Cost Light Fidelity (Li-Fi) System Employing On-Off Keying Data Modulation in Half-Duplex Asynchronous Transmission Mode

In recent years, Light Fidelity (LiFi) technology has gained more and more attention due to its ability to transmit large data in a short time, and prevents interference and radiation compared to conventional WiFi communication. Therefore, it is more preferable to be employed in health care related sector. In this paper, a low cost wireless data communication using Li-Fi Technology is presented. This project employed On-Off Keying (OOK) Modulation Technique to encode and decode messages. A pair of prototype transceivers were developed and adapting Half-Duplex Asynchronous Transmission Mode. The overall hardware is employing Arduino Nano and LEDs and hence the price was kept around USD 25. The entire system was being tested on four different aspects and they were data transmission duration, distance between transceivers, the transmission angle of the transceivers and the message capacity. These tests were being evaluated by Word Error Rate (WER) to acquire the accuracy. In short, the transceivers were able to transmit and receive all the alphabets, numbers and symbols on the ASCII computer keyboard. It works optimally with the transceiver angle of ±10° in a distance of 20cm with the minimum delay of 102ms. The data modulation techniques and the hardware selection were believed as the factors to improve the system performance.

Prototype of Visible Light Communication Transceiver Using Array Photo Transistor for Real Time Digital Media Transfer

Previous research about low cost visible light communication (VLC) transceiver prototype was conducted which able to reach 98 cm, 70° and 19200 bps of transmitting distance, maximum transmission angle and transmission rate, respectively. The next prototype is built to get better performance by adding a reflector to the array phototransistor and split the power of the transceiver in order to maximize the light of the LED. This new prototype surpasses our target by reaching 134 cm of transmission distance. The system is also able to send digital multimedia files such as text, images, video in MPEG format and audio files in WAV and Mp3 format. The maximum bit rate of our prototype is 9600 bps and acceptance angle is 87°.