Short-range Data Communication Research Articles

Numerical Investigation of Optical and Photoelectric Properties for 850 nm VCSELs with Arbitrary Crystal Orientation

High-speed VCSELs are widely used for high-capacity, short-range data communication links. Here, we numerically investigate the optical and electronic properties of a crystal orientation-dependent 1.06% compression InGaAs-AlGaAs laser emitting around 850 nm. The reduction of the density of states is observed in the largest energy range for the quantum well in the (110) orientation compared with the conventional (001) orientation. The calculated transparency carrier density decreases from 2.74 × 1018 cm−3 to 1.88 × 1018 cm−3 with the gain coefficient rising from 4969.4 cm−1 to 5427.2 cm−1 in (110) orientation. The 3 dB bandwidth of 31.25 GHz is realized in the (110) orientation, which can support 60 Gbps (NRZ) applications.

DAC-Less PAM-4 Slow-Light Silicon Photonic Modulator Providing High Efficiency and Stability

We report a slow-light silicon modulator that enables high-speed PAM operation without using an electrical digital-to-analogue converter (DAC). Bragg grating resonators, integrated into each arm of a Mach-Zehnder modulator, enhance the phase modulation through the slow light effect. The optical 4-level PAM signal is generated by driving directly the segmented phase shifter design with two binary signals. This modulator presents an ultra-compact footprint (L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SL-MZM</sub> = 570 μm), low energy consumption (73 fJ/bit), large electro-optic bandwidth (>40 GHz). Up to 90 Gb/s is achieved over an nm-range spectral operation bandwidth (Δλ = 2 nm). Compared to other low-energy resonator-based modulators, such as micro-rings, this operating bandwidth confers higher stability with a potential operating temperature range of ΔT = 50 °C. We further examine the robustness of the proposed design to fabrication variations by measurements of spectral properties across the wafer. This modulator is of particular interest for applications, such as short-range data communications that require multiple compact and energy-efficient modulators on a single chip.

OCDMA and OSTBC based VLC transceiver design using NI cDAQ

Visible light communication (VLC) is a novel technology especially for short-range data communication. IEEE has standardized VLC for 5G systems as a means to short-range wireless communication. In this paper, a complete state-of-the-art VLC software-defined radio is designed using NI cDAQ components tools developed in LabVIEW/MATLAB. The main objectives in designing a VLC transceiver are the suitable envelope for driving LEDs (transmitters) and a high data rate. The current work makes use of optical code division multiple access mainly to achieve the said objectives. It is shown through comparison with existing system that the proposed system is computationally less expensive and provides improved data rate. Finally, simulation programs are also developed and the proposed system is compared with the existing system in terms of bit error rate.

Packet Size Optimization for Cognitive Radio Sensor Networks Aided Internet of Things

Cognitive radio sensor networks (CRSNs) is the state-of-the-art communication paradigm for power constrained short range data communication. It is one of the potential technologies adopted for Internet of Things (IoT) and other futuristic machine-to-machine-based applications. Many of these applications are power constrained and delay sensitive. Therefore, CRSN architecture must be coupled with different adaptive and robust communication schemes to take care of the delay and energy efficiency at the same time. Considering the tradeoff that exists in terms of energy efficiency and overhead delay for a given data packet length, it is proposed to transmit the physical layer payload with an optimal packet size (OPS) depending on the network condition. Furthermore, due to the cognitive feature of CRSN architecture overhead energy consumption due to channel sensing and channel handoff plays a critical role. Based on the above premises, in this paper, we propose a heuristic exhaustive search-based Algorithm-1 and a computationally efficient suboptimal low complexity Karuh–Kuhn–Tucker (KKT) condition-based Algorithm-2 to determine the OPS in CRSN architecture using variable rate m-QAM modulation. The proposed algorithms are implemented along with two main cognitive radio assisted channel access strategies based on distributed time slotted-cognitive medium access control (DTS-CMAC) and centralized common control channel-based cognitive medium access control (CC-CMAC) and their performances are compared. The simulation results reveal that proposed Algorithm-2 outperforms Algorithm-1 by a significant margin in terms of its implementation time. For the exhaustive search-based Algorithm-1 the average time consumed to determine OPS for a given number of cognitive users is 1.2 s, while for KKT-based Algorithm-2, it is of the order of 5–10 ms. CC-CMAC with OPS is most efficient in terms of overall energy consumption but incurs more delay as compared to DTS-CMAC with OPS scheme.

Health Monitoring System Based on Intra-Body Communication

This paper presents a model of a Body Area Network (BAN) health monitoring system based on Intra-Body Communication. Intra-body Communication (IBC) is a communication technique that uses the human body as a medium for electrical signal communication. One of the visions in the health care industry is to provide autonomous and continuous self and the remote health monitoring system. This can be achieved via BAN, LAN and WAN integration. The BAN technology itself consists of short range data communication modules, sensors, controller and actuators. The information can be transmitted to the LAN and WAN via the RF technology such as Bluetooth, ZigBee and ANT. Although the implementations of RF communication have been successful, there are still limitations in term of power consumption, battery lifetime, interferences and signal attenuations. One of the solutions for Medical Body Area Network (MBANs) to overcome these issues is by using an IBC technique because it can operate at lower frequencies and power consumption compared to the existing techniques. The first objective is to design the IBC's transmitter and receiver modules using the off the shelf components. The specifications of the modules such as frequency, data rate, modulation and demodulation coding system were defined. The individual module were designed and tested separately. The modules was integrated as an IBC system and tested for functionality then was implemented on PCB. Next objective is to model and implement the digital parts of the transmitter and receiver modules on the Altera's FPGA board. The digital blocks were interfaced with the FPGA's on board modules and the discrete components. The signals that have been received from the transmitter were converted into a proper waveform and it can be viewed via external devices such as oscilloscope and Labview. The signals such as heartbeats or pulses can also be displayed on LCD. In conclusion, the IBC project presents medical health monitoring model that operates at the range of 21 MHz frequency and reduce the power consumption for a longer battery lifetime.

Reduced-size circularly polarised square microstrip antenna for 2.45 GHz RFID applications

This study proposes a new design of circular polarised (CP), microstrip (patch) antenna using a set of slits and slots to effectively reduce the area of patch by 67% compared with the conventional, corner truncated, circular polarised square patch. The antenna is designed to operate at 2.45%GHz in the Industrial-Scientific-Medical (ISM) band and has many applications in short-range data communications such as in wireless sensors, radio frequency identification and personal area networking. The proposed antenna has been simulated using HFSS. The design has been fabricated and an extensive measurement campaign has confirmed simulation results. The proposed antenna has a low bore-sight axial ratio of 0.77 dB and a 10 dB bandwidth of 70 MHz. The overall antenna size is 19.6 mm x 19.6 mm on a substrate of thickness 1.59 mm. A second design with a more complex network of slots and slits achieves similar performance in simulation with an overall side length of 13.2 mm, but at the cost of a much larger input impedance.

Emergency Handling for MAC Protocol in Human Body Communication

The human body communication (HBC) is a technology that enables short range data communication using the human body as a medium, like an electrical wire. Thus it removes the need for a traditional antenna. HBC may be used as a type of data communication in body area network (BAN), while the devices are being in contact with body. One of important issues in BAN is an emergency alarm because it may be closely related to human life. For emergency data communication, the most critical factor is the time constraint. IEEE 802.15.6 specifies that the emergency alarm for the BAN must be notified in less than 1 sec and must provide prioritization mechanisms for emergency traffic and notification. As one type of BAN, the HBC must follow this recommendation, too. Existing emergency handling methods in BAN are based on the carrier sensing capability on radio frequencies to detect the status of channels. However, PHY protocol in HBC does not provide the carrier sensing. So the previous methods are not well suitable for HBC directly. Additionally, in the environment that the emergency rate is very low, the allocation of dedicated slot(s) for emergency in each superframe is very wasteful. In this work, we proposed specific emergency handling operation for human body communication's medium access control (HBC-MAC) protocol to meet the emergency requirements for BAN. We also showed the optimal number of emergency slots for the various combinations of beacon intervals and emergency rates.

Design and Implementation of Energy-Collection-Based Low Complexity IR-UWB Receiver

In this paper, an energy-collection-based non-coherent IR-UWB receiver allowing low complexity and low power consumption is proposed for short range data communication. The proposed receiver consists of an on-the-fly integrator, a 1-bit digital sampler, a pre-processor and a digital symbol synchronizer. The on-the-fly integrator for energy collection and the 1-bit digital sampler reduce complexity of IR-UWB system. Furthermore, with a simple digital filter in the pre-processing unit, SNR and robustness of the receiver against time-varying channel are enhanced. Also the receiver complexity is diminished by a simple scheme of symbol synchronization based on rough time information about incoming pulses, not requiring exact timing information. The performance of the proposed receiver is simulated based on IEEE 802.15.4a channel model and the algorithms are implemented and verified on a FPGA.

Mixed signals [Zigbee

We are now - if the vendors involved are to be believed - living in the age of ZigBee. Like Bluetooth, it mainly operates in the licence-exempt industrial, scientific and medical (ISM) band around 2.4GHz. Unlike Bluetooth, which is predominantly used for wireless headsets, it is intended for short range data communications between `intelligent&apos; devices. This puts in firmly in the industrial and commercial sector, as opposed to Bluetooth which now sits almost exclusively in the consumer space. The focus on industrial and not consumer applications means ZigBee faces a difficult challenge; it needs to offer the performance demanded by industrial and commercial applications, but with a competitively low price tag when compared to existing proprietary implementations - both wired and wireless - in a highly fragmented marketplace.

A low-complexity noncoherent IR-UWB transceiver architecture with TOA estimation

Impulse-radio (IR)-based ultra-wideband (UWB) technology is a strong candidate for short-range data communication and positioning systems. This paper examines the performance of time-of-arrival (TOA) position estimation techniques as well as the simulated and measured performances of an IR-UWB noncoherent energy-collection receiver. The noncoherent IR-UWB transceiver has been designed for operation over the frequency range 3.1-4.1 GHz and implemented in 0.35-/spl mu/m SiGe BiCMOS technology. The performance of two different algorithms, namely, the threshold-crossing and the maximum selection (MAX) algorithms, are compared in terms of TOA estimation error in Saleh Valenzuela channel model 3 and channel model 4. The implemented structure of the TOA MAX algorithm suitable for IR-UWB-based noncoherent receivers is presented. A UWB testbed has been constructed in order to test and measure the transmitted waveform as well the receiver performances. The simulated receiver noise figure is 7.3 dB while the receiver gain is 34 dB. The TOA MAX algorithm can achieve /spl plusmn/5-ns positioning accuracy for 95% of cases. Constant transconductance tuning circuits for improved TOA estimation reliability are also presented.

An Energy-Harvesting Wireless-Interface SoC for Short-Range Data Communication

This paper describes design and verification of a wireless-interface SoC (system-on-a-chip) for a wireless battery-less mouse with short-range data-communication capability. The SoC comprises an RF transmitter and microcontroller. The SoC, which is powered by an electric generator that exploits gyration energy by dragging the mouse, was fabricated using a TSMC 0.18-um CMOS process. The features of the SoC are the adoption of a simple FSK modulation scheme, single-end configuration on the RF transmitter, and specific microcontroller design for mouse operation. We verified that the RF transmitter can make data communication within a 1-m range at 2.17 mW, and the microcontroller consumes 0.03 mW at 1 MHz, which exhibits that the total power consumption is 2.2 mW. This is sufficiently low for the SoC to operate with energy harvesting.

Close encounters of the magnetic kind [near field communications

This article discusses electromagnetic induction used for near field communications. It begins by outlining magnetic fields, and the difference between near field and far field propagation. It then describes various applications which could make use of near field propagation. These include: short range data communications; medical implants; and human interfaces requiring position sensing.

Development of CMOS integrated optical receiver for short‐range data communication

AbstractReduction of the size and cost of optical receivers is important to the proliferation of optical communications technology for short‐distance communications. In the present research, an integrated optical receiver is fabricated with a standard 0.35‐µm CMOS process targeting the POF optical transmission system. A photodiode, a trans‐impedance amplifier, a limiting amplifier, and a buffer are integrated in this optical receiver. The photodiode is formed with an N‐well and a P‐diffused layer of stripe configuration and has an optical receiving surface area of 150 × 150 µm and a response sensitivity of about 0.04 A/W (at a wavelength of 650 nm). In the CMOS process, the large junction capacitance of the photodiode is problematic. Therefore, the input impedance of the circuit is lowered by means of an RGC‐type trans‐impedance amplifier and LC resonance is suppressed by optimization of the package and circuit. The chip is mounted in a small ceramic package for measurement. Excellent eye patterns are obtained. The minimum receiving sensitivity for a bit error rate of less than 10−9 is −10 dBm at 600 Mbit/s and −4.5 dBm at 1 Gbit/s. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 87(12): 10–18, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20099

Performance modeling of the IrDA protocol for infrared wireless communications

This article presents a performance analysis of the IrDA protocol used for short-range IR data communication using an analytical mathematical model. The IrDA protocol specifies a protocol stack for reliable short-range infrared wireless data communication between devices with the data link layer (IrLAP) being an HDLC derivative. The mathematical model is based on unidirectional data transfer and uses the concept of the virtual transmission time, which provides the average end-to-end transmission time of a packet, incorporating the time for retransmissions if packet errors occur or other enforced delays. Analytical results are produced for throughput against packet size, BER and minimum turnaround time. They indicate certain limitations of the protocol for efficient throughput at high data speeds, and indicate that the maximum frame size and window size should be increased and the minimum turnaround time minimized for improved results.