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RF spectrum represents a limited natural resource. The increasing numbers of wireless devices demand more and more spectrum for diverse future applications and services. CR is explored as a technological solution to the current paradigm of spectrum scarcity by opportunistically sharing the spectrum with licensed users. FD operation further enhances the performance of CR with higher throughput and optimized sensing time. Tactical radios are traditionally operated in the licensed frequency bands. To comply with the soaring demands, alternative means are explored to share the spectrum among tactical users. In this article, an FD-CR integrated with tri-band operation and dynamic spectrum shaping is proposed for tactical communications. The proposed radio is implemented in the Zynq SDR platform. The performance results reveal that the FD-CR offers higher throughput, higher probability of detection (Pd > 0.9), and optimized sensing time, which empowers the system to be ideally suitable for tactical communication networks. [ABSTRACT FROM AUTHOR]

Abstract: This letter proposes a double‐pole double‐throw (DPDT) switch with high isolation and high linearity using a 65‐nm CMOS process. To improve the isolation, resonant inductors are employed for the core switches, which are composed of a single‐stacked NMOS with gate‐body floating techniques. And, the switch is controlled by a cross‐biasing technique to increment the power linearity. The active circuits are designed separately from the passive elements to reduce the interference. The core area of the proposed switch excluding all of the pads is 380 × 300 μm2. The minimum insertion loss is 2.57 dB at 23 GHz and maximum isolation is 39.7 dB at 26 GHz, respectively. The third‐order intermodulation intercept point (IIP3) is 37 dBm at 28 GHz. [ABSTRACT FROM AUTHOR]

In view of the requirements for high-speed, highly reliable wireless implant communication, we have developed an implant transceiver working at a 10–60-MHz band. The developed transceiver is based on an impulse radio technology with multipulse position modulation to increase the communication speed and reliability, and utilizes the automatic equalization technique to suppress waveform distortion and intersymbol interference due to frequency-dependent tissue properties. The transmit antenna has a dimension of $2.6\,\,\text {cm} \times 1.6\,\,\text {cm} \times 1.6$ cm and a relative bandwidth of 16% by forming the radiation elements on a flexible magnetic sheet for miniaturization. Through an in vivo experiment on a living swine, we have shown the feasibility of implant communication in a depth up to 26 cm with a minimum data rate of 10 Mbps. These results demonstrate the superiority of this new technology over all others reported so far in the literature. [ABSTRACT FROM AUTHOR]

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This paper proposes a split power-driving scheme for electromagnetic interference robust design and its automatic stepwise digital slope control for suppression of spectral emission. This analog–digital hybrid method gives power saving effect up to 24.4%, and also production reliability can be improved by utilizing a failure detection and recovery scheme. For feasibility of the proposed electromagnetic compatibility (EMC) scheme, a Local Interconnect Network transceiver prototype is fabricated in a 0.18-μm BCD process, and experimentally verified to provide EMC-enhanced operation with low-cost and low-power overheads. [ABSTRACT FROM AUTHOR]

Cognitive radio is a promising technology for improving spectrum utilization, which allows cognitive users access to the licensed spectrum while primary users are absent. In this paper, we design a resource allocation framework based on graph theory for spectrum assignment in cognitive radio networks. The framework takes into account the constraints that interference for primary users and possible collision among cognitive users. Based on the proposed model, we formulate a system utility function to maximize the system benefit. Based on the proposed model and objective problem, we design an improved ant colony optimization algorithm (IACO) from two aspects: first, we introduce differential evolution (DE) process to accelerate convergence speed by monitoring mechanism; then we design a variable neighborhood search (VNS) process to avoid the algorithm falling into the local optimal. Simulation results demonstrate that the improved algorithm achieves better performance. [ABSTRACT FROM AUTHOR]

A high-coupling-efficiency and convenient-integration transmitter optical subassembly for 25 Gbps small-form transceiver is developed in this paper. In the structure, the VCSEL is vertically mounted on the silicon substrate by the flip-chip method to enable direct and passive alignment with the fibers plugging in the fiber guide holes on the silicon substrate. By the optical simulation, the maximum coupling efficiency of VCSEL is −0.38 dB. The vertical electrical pads of the VCSEL are connected to the horizontal wire-bonding pads on silicon substrate by the 90°-bend GS micro strip lines. Thus, the interconnection between the transmitter optical subassembly and the electrical PCB board is conveniently realized by the low-cost wire-bonding method. The electrical performance of the 90°-bend GS micro strip lines on the optical subassembly is also evaluated by the 3D electromagnetic simulation. In order to verify the transmission performance of the transmitter optical subassembly, it is integrated with an electrical board using bonding wires, and then the optical performance of the transmitter is measured. By the measurement, the optical subassembly can operate up to 25 Gbps per channel. [ABSTRACT FROM AUTHOR]

A highly linear receiver (RX) front end with integrated hybrid transformer (HT) for frequency-division duplexing mobile communications is reported. The HT, implemented with a three-winding coplanar transformer, is used to interface the RX front end with the antenna and the power amplifier. The primary is driven at its center tap with the transmitted signal and at one input with the antenna signal, while the other input is connected to an on-chip programmable balancing impedance. The two secondary drives a differential push–pull common-gate low-noise amplifier (LNA). Assuming a perfectly linear hybrid only 45 dB of transmitter (TX)–RX isolation and 35 dB of common-mode rejection are required to meet the intermodulation specs thanks to the +25-dBm receiver IIP3. This would drastically simplify hybrid balancing and adaptation loop. Cascaded noise figure of duplexer, LNA, and baseband is below 6.7 dB and TX insertion loss below 4.3 dB from 1.7 to 2.1 GHz. The implemented prototype in 28-nm CMOS has an active area of 0.7 mm2 and requires only 26 mW. [ABSTRACT FROM PUBLISHER]

Cooperative diversity techniques have been utilized to improve the energy efficiency of wireless sensor networks (WSNs) operating over flat fading channels in a considerable number of literature. However, wireless channels of WSNs operating in indoor environments are supposed to be characterised by frequency-selective fading. Theoretical analysis of energy efficient cooperative communications in WSNs operating in indoor environments are rarely addressed. Therefore, this paper studies the energy efficient cooperative communications in WSNs operating over frequency-selective fading channels. Closed-form bit error rate expressions are derived for systems over frequency-selective fading channels. In order to fully explore the energy conservation potential of cooperative communications, solutions of the optimal transmit power allocation and the partner node selection are provided. Moreover, it is proven that the communication quality can be greatly improved by using chip-interleaving techniques in WSNs subject to flat fading channels. Thus, this paper investigates the energy-saving potential of chip-interleaved transceivers in WSNs subject to frequency-selective fading. Numerical results show that significant energy savings can be achieved via cooperations with chip-interleaved transceivers in WSNs operating in indoor environments. [ABSTRACT FROM AUTHOR]

We present a versatile electro-optical packaging platform for optical transceiver modules suitable for very high aggregate I/O capacity, as required, for example, in (disaggregated) datacenters and servers. Real-estate limitations on the board or on the processor package laminate are overcome by using a flexible printed circuit board substrate that is folded around a solid body, resulting in a 3-D package assembly. A 48 \text Gb/s \times 10 Gb/s transceiver prototype is demonstrated as well as the design path toward a transceiver with 1.2-Tb/s aggregate I/O bandwidth. Accounting for large-scale manufacturing and deployment, we explicitly address the requirements of the optical, mechanical, thermal, and electrical interfaces as well as of all associated manufacturing processes. [ABSTRACT FROM AUTHOR]

This paper considers the localization of an emitter where the transmitted signal is unknown for receivers. To improve the localization accuracy, we propose an efficient method to estimate the emitter position by reconstructing the transmitted signal jointly. Simulation results show that the localization performance of the proposed method is much better than the existing algorithms. [ABSTRACT FROM AUTHOR]

Direct-conversion architectures can offer highly integrated low-cost hardware solutions to communication transceivers. However, it has been demonstrated that radio frequency (RF) impairments such as amplifier nonlinearities, phase noise, and in-phase/quadrature-phase imbalances (IQI) can lead to severe degradation of the performance of such systems. Motivated by this, the present work is devoted to the quantification and evaluation of the effects of RF IQI on wireless communications in the context of cascaded fading channels for both single-carrier and multicarrier systems. To this end, closed-form expressions are first derived for the outage probability (OP) over N^\ast Nakagami-$m$ channels for the cases of ideal transmitter (TX) and receiver (RX), ideal TX and IQI RX, IQI TX and ideal RX, and joint TX/RX IQI. The offered expressions, along with several deduced corresponding special cases, are subsequently employed in vehicle-to-vehicle (V2V) communications to justify their importance and practical usefulness in the context of emerging communication systems. The offered analytic results are corroborated by extensive comparisons with respective results from computer simulations. It is shown that considering non-ideal RF front-ends at the TX and/or RX introduces nonnegligible errors in the OP performance that can exceed 20% under several communication scenarios. It is further demonstrated that the effects by cascaded multipath fading conditions are particularly detrimental as they typically result in considerable performance losses of around or over an order of magnitude. [ABSTRACT FROM PUBLISHER]

This paper presents a fully integrated reconfigurable all-band RF transceiver for GPS/GLONASS/ Galileo/Beidou in 55-nm CMOS. The transceiver incorporates three low-IF receivers (RXs) and one direct up-conversion BPSK transmitter (TX), which can be configured to receive any two global navigation satellite system (GNSS) signals or switched to process the Chinese Beidou(I) signals. A switching module is integrated to provide the connectivity between different RF front-end and IF channel (IFC), which will effectively simplify the design complexity of the IFC and save power consumption, while the GNSS signals are received. A flexible frequency plan with two frequency synthesizers is utilized to satisfy different local oscillator requirements of the transceiver. An optimized automatic frequency calibration scheme using an error compensation logic enables fast and high-precision calibration process for optimum phase-locked loop operation. Several digitally assisted calibration modules are integrated to ensure that the chip performance only shows a weak process, voltage and temperature (PVT) dependence. While drawing about 21.5–30.2 mA per RX channel from a 1.2-V supply, the RXs achieve an image rejection ratio more than 49 dB after I/Q mismatch calibration, an automatic gain control range of 88 dB, and an input-referred 1 dB compression point of better than −25 dBm with a minimum noise figure of about 2 dB. The output power of the TX is about 5 dBm with about 6% error vector magnitude (EVM) and 30-mA current from a 1.2-V supply. The whole transceiver consumes a die area of 2.8 \times 3~mm^2 . [ABSTRACT FROM AUTHOR]

This paper presents a novel pipelined analog-to-digital converter (ADC) with a dB-linearity automatic gain control (AGC) loop that exhibits both power and area efficiencies for low-rate wireless personal area network (LR-WPAN) receiver applications. The AGC loop is designed based on feedback architecture for high linearity and a full-digitally control method is proposed to simplify the gain adjusting. The sample-and-hold amplifier less (SHA-less) scheme is employing in ADC design, and moreover, an evaluation-time-sharing technique which combined opamp- and capacitor-sharing is presented for low power consumption and elimination of memory effect. The proposed circuit shows a gain error less than ±0.56 dB in a wide dynamic range of about 70 dB by 2 dB/step and achieves a maximum IIP3, SNDR, SFDR of 16.27 dBm, 41.87 dB, 58.72 dB, respectively. Designed in a 0.18 μm CMOS technology, the proposed circuit has been integrated in the LR-WPAN transceiver. The chip area is as small as 0.94 mm and the total power consumption is only 7.62 mW from a 1.8 V single supply. [ABSTRACT FROM AUTHOR]

We consider joint source/relay precoding in three-node two-hop amplify-and-forward (AF) multiple-input–multiple-output (MIMO) relay systems. In our systems, linear precoders are used at the source and the relay, and the QR successive interference cancelation (SIC) receiver is used at the destination. Our design criterion is to minimize the block error rate (BLER) of the receiver. Since the BLER is a complicated function of the source and relay precoders, and the power constraints are coupled, the optimization problem is difficult to solve. To overcome the difficulty, we first apply the primal decomposition approach, transforming the original optimization to a subproblem and a master problem. In the subproblem, the optimum source precoder can be obtained with the geometric mean decomposition (GMD). In the master problem, however, the optimum relay precoder cannot be straightforwardly obtained. We theoretically prove that the optimum relay precoder exhibits a matrix diagonalization property. Using this property, we can then transform the master problem into a scalar-variable concave optimization problem. A closed-form solution can be derived by the Karuch–Kuhn–Tucker (KKT) conditions. Finally, we extend our method to the two-hop AF MIMO relay system with the minimum mean square error (MMSE) SIC receiver. Assuming a unitary source precoder, we obtain the optimum source and relay precoders in closed form. Simulations show that the proposed transceivers can significantly improve the system performance. [ABSTRACT FROM PUBLISHER]

This paper proposes a novel object tracking method using radio interferometry. The proposed low cost solution is able to track objects, equipped with a radio receiver, in real time, using only simple infrastructure nodes with radio transceivers at fixed and known locations. The localization method has low computational requirements and does not require any preliminary knowledge of, or measurements in the space where tracking is performed. The paper introduces the novel method and preliminary test results are also presented. [ABSTRACT FROM AUTHOR]

This study aims to implement the telematics between hybrid rockets and the ground receiving station. In order to significantly reduce the rocket weight, fibre-reinforced plastic is used for the hybrid rocket casing, on which coplanar wraparound antennas with an operating frequency of 433 MHz are designed. The antenna structure contains three coplanar printed patches, among which the middle printed patch is the primary radiator and the resonant length appears a wavelength for the metallic surface case. An RF module with high receiver sensitivity and a high-power power amplifier are included to enhance the communication coverage of hybrid rockets and the ground receiving station so that the station can effectively track the hybrid rocket. Finally, the radio wave propagation model is used for calculating the link budget such that the communication coverage between rocket transmitters and the ground receiving station can be estimated, and on-site measurement and verification are preceded. [ABSTRACT FROM AUTHOR]

In this paper, we propose cognitive overlay transceiver designs, where a primary transceiver pair and a secondary transceiver pair coexist in a network, and the primary user (PU) allows the secondary user (SU) to concurrently transmit its signals at the price of reducing the power of the PU's signal relayed by cooperative amplify-and-forward (AF). Since the considered transceiver design is mainly to devise the precoders both for the PU and the SU at the secondary transmitter (ST), the channel state information (CSI) has to be known at the ST. We therefore consider the limited feedback scheme with random vector quantization (RVQ), where the ST can only know the quantized channel direction information (CDI). Considering the statistics of the CSI quantization error and the linear minimum mean square error (LMMSE) receiver, we derive the closed-form MSE expressions corresponding to the PU and the SU. With the derived MSEs, we propose two robust design criteria. One criterion is to minimize the ST's power consumption under the constraint that the PU's and SU's quality-of-service (QoS; i.e., MSE) can be met. The other criterion is to minimize the SU's MSE when the PU's QoS can be controlled under a certain value and the ST satisfies the limitation of its transmission power consumption. Both the optimization problems of the proposed design criteria are not convex, and the corresponding solutions cannot be directly obtained. We then propose transfering the original optimization problems into two subproblems, where each of them is eventually formulated as a convex optimization problem, and the solutions are iteratively obtained, which is effective. Thus, the results can be obtained with the interior-point method. Simulations certify the robustness of our designs. [ABSTRACT FROM PUBLISHER]

This paper addresses the modeling and cancellation of self-interference in full-duplex direct-conversion radio transceivers, operating under practical imperfect radio frequency (RF) components. First, detailed self-interference signal modeling is carried out, taking into account the most important RF imperfections, namely, transmitter power amplifier nonlinear distortion as well as transmitter and receiver IQ mixer amplitude and phase imbalances. The analysis shows that after realistic antenna isolation and RF cancellation, the dominant self-interference waveform at the receiver digital baseband can be modeled through a widely linear transformation of the original transmit data, opposed to classical purely linear models. Such widely linear self-interference waveform is physically stemming from the transmitter and receiver IQ imaging and cannot be efficiently suppressed by classical linear digital cancellation. Motivated by this, novel widely linear digital self-interference cancellation processing is then proposed and formulated, combined with efficient parameter estimation methods. Extensive simulation results demonstrate that the proposed widely linear cancellation processing clearly outperforms the existing linear solutions, hence enabling the use of practical low-cost RF front ends utilizing IQ mixing in full-duplex transceivers. [ABSTRACT FROM PUBLISHER]

Recently, DFT-based oversampled perfect reconstruction filter banks (OPRFB), as a special form of filtered multitone, have shown great promises for applications to multicarrier modulation. Still, accurate frequency synchronization and channel equalization are needed for their reliable operation in practical scenarios. In this paper, we first derive a data-aided joint maximum likelihood (ML) estimator of the carrier frequency offset (CFO) and the channel impulse response (CIR) for OPRFB transceiver systems operating over frequency selective fading channels. Then, by exploiting the structural and spectral properties of these systems, we are able to considerably reduce the complexity of the proposed estimator through simplifications of the underlying likelihood function. The Cramer Rao bound on the variance of unbiased CFO and CIR estimators is also derived. The performance of the proposed ML estimator is investigated by means of numerical simulations under realistic conditions with CFO and frequency selective fading channels. The effects of different pilot schemes on the estimation performance for applications over time-invariant and mobile time-varying channels are also examined. The results show that the proposed joint ML estimator exhibits an excellent performance, where it can accurately estimate the unknown CFO and CIR parameters for the various experimental setups under consideration. [ABSTRACT FROM AUTHOR]

Fixed-latency serial links are important components of the distributed measurement and control systems. However, most high-speed Serializer-Deserializer (SerDes) chips do not keep the same link latency after each power-up or reset. In this paper, we propose a fixed-latency serial transceiver based on dynamic clock phase shifting and changeable delay tuning technologies. Our solution can process all possible phase offsets between the transmitted and received clocks, so it relaxes the requirement of fanning in the same reference clock both to the transmitter and to the receiver. It also eliminates the reset-relock process in the roulette approach. We present a specific example of implementation based on the serial transceiver in Xilinx Virtex 5 FPGA. The experiment results indicate that our transceiver can achieve a deterministic latency with sub-nanosecond precision. [ABSTRACT FROM PUBLISHER]

The ultra-wide bandwidth released for unlicensed use by FCC a decade ago has initiated significant research efforts. The large ultra-wide bandwidth is attractive not only for increased data transfer speed but may also be exploited for added functionality like high-precision ranging in wireless sensor networks. RAKE based receivers are preferred for ultra-wideband (UWB) technology due to wide bandwidth. However, designing RAKE based correlating receivers remains quite challenging. Correlating receivers are also power consuming due to high-speed DSPs, ADC and matched filter. Timing synchronization is another issue associated with correlating receivers. In this paper a impulse radio ultra-wideband (IR-UWB) RAKE receiver is presented utilizing a continuous-time binary value coding scheme for power-efficiency and coherent symbol detection without the need for synchronization to achieve precise ranging using time-of-flight technique. A working prototype of the IR ranging transceiver which uses the IR-UWB RAKE receiver is presented with measured high-precision ranging towards 1.4 cm. [ABSTRACT FROM AUTHOR]

The main target of a 60 GHz transceiver system is to obtain data rates close to gigabit per second over short distances. The 60 GHz band suffers from severe path-loss, inter-symbol interference (ISI) and a limited link budget. To improve the link budget, we need to utilize beam-forming (BF) techniques. Antenna BF, i.e., combining signals from multiple receive antennas is one of the crucial aspects of the 60- GHz transceiver system. We consider uniform linear and circular antenna arrays for the proposed BF scheme. We use single carrier with frequency domain equalization (SC-FDE) modulation scheme in our system model. To suppress the ISI, we considered a cyclic prefix in the SC-FDE. The effects of physical parameters of antenna arrays on the bit error rate (BER) were investigated assuming both line of sight (LOS) and non-line of sight scenarios. We developed an efficient and computationally less complex beam-forming algorithm (BFA). We investigated the effects of perfect channel and non-perfect channel on the BER performance using the proposed BFA. We presented that the BER and sever ISI of 60 GHz band also improves using the proposed BFA. [ABSTRACT FROM AUTHOR]

This paper presents a new method for automatic radio spectrum segmentation. Spectrum segmentation serves as a first step to identify the subbands that are in use at a certain time, when a wide portion of the spectrum is observed. The proposed method, based on the evaluation of the histogram of the power spectral density of the received signal, is designed for obtaining a low processing complexity and to be implemented in a measurement instrument or a cognitive radio receiver. The proposed method is validated on emulated signals, and the results show good accuracy of the subband boundary estimation and a processing complexity much lower than the other segmentation methods. [ABSTRACT FROM PUBLISHER]

This paper presents a propagation model and inductive link budget based on link equations for chains of inductive loops as the basis for determining the link budget of inductive communication and wireless power transfer systems. The link between the transmitter and receiver is modeled in similar format as in radio frequency systems. The transmitter antenna gain, path loss model and receiver antenna gain are also modeled for the inductive case. This allows the magnetic path loss to be estimated accurately. Also the induced receiver current due to a transmitter voltage can be computed apriori enabling efficient design of inductive links and transceivers. [ABSTRACT FROM AUTHOR]

This paper proposes a linear transmit filter design to maximize weighted sum capacity (WSC) in multiuser multiple-input–multiple-output (MU-MIMO) systems. The proposed scheme is based on a modified signal-to-leakage-plus-noise ratio (SLNR) criterion, which integrates receiver structures and power allocations into the precoder design and can efficiently exploit unused receiver subspaces. Based on the proposed transmitter (TX) design with receive matched filters (MFs), the WSC maximization problem can be simplified to power-allocation and data-stream selection problems. A power-allocation algorithm for finding a local optimal solution is also proposed and is shown to be obtained by the iteration of closed-form water-filling (WF) solutions. Furthermore, a low-complexity user and substream selection is proposed as an alternative solution to maximize WSC. Simulation results show that the proposed algorithms outperform the conventional scheme and achieve comparable performance to a joint transceiver design, despite requiring simpler receiver structures. [ABSTRACT FROM PUBLISHER]

In this paper, we study a subcarrier-and-power-allocation problem for orthogonal-frequency-division multiple-access (OFDMA)-based cognitive radio (CR) systems. In a departure from existing works in the literature that considered resource allocation for either an overlay spectrum access mechanism (OSAM) or an underlay spectrum access mechanism (USAM), we propose subcarrier-and-power-allocation schemes for a joint overlay and underlay spectrum access mechanism (JOUSAM). In particular, for such a CR system, the total transmission rate of CR users is maximized for a given power budget while keeping the interference introduced to the primary-user (PU) receivers' below given thresholds with a certain probability. As the optimal scheme can be highly complex, we also propose a low-complexity suboptimal subcarrier-and-power-allocation scheme. The selected numerical results show that a significant gain in terms of total achievable transmission rate can be obtained over an USAM or an OSAM. These selected numerical results also show that the proposed suboptimal scheme, which has a very low complexity, provides a significant improvement in performance over either underlay or overlay spectrum access mechanism. The proposed optimal scheme can lead to an unfairness among CR users in sharing the total transmission rate; therefore, we also propose a suboptimal subcarrier-allocation scheme that can guarantee a certain level of fairness among CR users. [ABSTRACT FROM PUBLISHER]

Strong jamming signals from colocated transmitters can cause intermodulation and desensitization in receiver circuits. Cancellation circuits can remove interference but generate noise and distortion of their own. We analyze such a system using a signal-to-interference-and-noise ratio (SINR) measure. We show that the cancellation coupler can be optimized to maximize the SINR. The optimum coupler value is proportional to the expected level of the jammers. A hardware prototype reduced the jammers by 46 dB in a controlled experiment and by 25 dB in an over-the-air experiment. A convergence time of 8.4 ms was sufficient for this application. [ABSTRACT FROM PUBLISHER]

In this paper, we introduce a method for inphase/quadrature imbalance parameter estimation based on ellipse fitting. The performance of the method is analytically derived. In particular, it is shown that the method exhibits a small bias (which can be negligible under some standard practical conditions) and a variance slightly above the Cramér–Rao bound. The method is then applied to measurements from a contemporary BiCMOS transceiver which is used on one of the most popular daughterboards of the universal software radio peripheral. In our measurements, the phase skew varies up to 5^\circ with the baseband frequency, while the amplitude imbalance varies between 0 and 0.3 dB over carrier frequencies and across hardware units. The time variation, however, is only 0.004 dB in amplitude and 0.06^\circ in phase. This indicates that the units could either be calibrated online when there is no transmission (in a two-antenna MIMO system, one antenna could transmit a calibration signal to the other), or they could be calibrated during production, in which case a table with different carrier and baseband frequencies would be needed. However, there is no need to estimate the parameters on every burst. [ABSTRACT FROM AUTHOR]

Who can imagine that soon our body can be the backbone of a broadband personal data network linking our mobile phone or MP3 player to a cordless headset, our digital camera to a PC or printer, and all gadgets one carries around to each other? This Can be achieved by using your body to create a high-speed computer network called Red Tacton-Human Area Network (HAN). In this paper we design and implemented Red Tacton by using VHDL a hardware descriptive language which describes the behavior of Electronic Circuit. Two way communications is also achieved by using Red Tacton [ABSTRACT FROM AUTHOR]

A multifunctional transceiver for future intelligent transportation systems (ITSs) is proposed and presented in this paper. The transceiver has two operation modes, namely, radar (sensing) mode and radio (communication) mode, which are realized within a single hardware platform. In the proposed transceiver architecture, a special modulation scheme is devised in which the radar mode and radio mode are arranged in different time slots. In the radar cycle, a trapezoidal frequency-modulation continuous-wave modulation scheme is adopted. The radio cycle following the radar cycle is simply an additional constant-frequency period of the transmitted signal, which can be used as a constant carrier for data transmission. To prove and demonstrate the functionality of the proposed transceiver system, an experimental prototype was designed and constructed in this study for 5.9-GHz dedicated short-range communication system applications. Both system simulation and measurement results show very good performances. This multifunctional transceiver system has demonstrated a number of advantages and features such as low cost, low complexity, and versatile functionality, which promises to play an important role in the development of future ITSs and other similar systems. [ABSTRACT FROM PUBLISHER]

This paper presents a fully integrated UWB-IR transceiver front-end operating in the 7.25–8.5 GHz band designed for high overall transmission and detection energy efficiency and robustness to interferers. The transceiver front-end features a pulsed transmitter that wakes up when triggered by a digital signal, generates a pulse, and automatically switches-off in less than 2 ns. The receiver includes an LNA, a VGA, a squarer, a windowed integrator, and a comparator to perform PPM demodulation of the data. A prototype of the transceiver front-end was integrated in a 0.13 \mu\m CMOS technology. The transmitter delivers 13 pJ/pulse to the antenna consuming about 190 pJ/b, with an efficiency \etaT=7\%, well in excess of comparable designs. Using pulse polarity scrambling, it complies with the FCC spectral emission limits up to a pulse repetition frequency (PRF) of 5 MHz. The receiver achieves a sensitivity of -87 dBm at a PRF of 100 kHz, and of -70 dBm at a PRF of 5 MHz, while consuming 4.2 mW. It can tolerate interferers up to -12 dBm at 5.4 GHz. [ABSTRACT FROM AUTHOR]

Interference limits performance in wireless networks and cooperation among receivers or transmitters can help mitigate interference by forming distributed MIMO systems. Earlier work refid="ref1"/ shows how limited receiver cooperation helps mitigate interference. The scenario with transmitter cooperation, however, is more difficult to tackle. In this paper we study the two-user Gaussian interference channel with conferencing transmitters to make progress towards this direction. We characterize the capacity region to within 6.5 bits/s/Hz, regardless of channel parameters. Based on the bounded-gap-to-optimality result, we show that there is an interesting reciprocity between the scenario with conferencing transmitters and the scenario with conferencing receivers and their capacity regions are within a bounded gap to each other. Hence, in the interference-limited regime, the behavior of the benefit brought by transmitter cooperation is the same as that by receiver cooperation. [ABSTRACT FROM PUBLISHER]

A high-frequency jitter tolerant receiver in 65 nm CMOS is presented. Jitter tolerance is improved by tracking correlated jitter using a pulsed clock forwarded from the transmitter side. The clock receiver comprises two injection locked oscillators to frequency-multiply, deskew, and adjust jitter tracking bandwidth. Different data rates and latency mismatch between the clock and data paths are accommodated by a jitter tracking bandwidth that is controllable up to 300 MHz. Each receiver consumes 0.92 pJ/bit operating at 7.4 Gb/s and has a jitter tolerance of 1.5 UI at 200 MHz. [ABSTRACT FROM AUTHOR]

This paper presents a transceiver that communicates over electronic textiles as an alternative, energy-efficient communication medium for body-area network (BAN) applications. The proposed eTextiles network architecture consists of a two-wire conductive yarn medium, body-worn nodes, and a basestation used for data collection and medium-access control. Fabricated in 0.18 \mum CMOS technology, the eTextiles transceiver employs supply-rail-coupled differential signaling to efficiently time-share the eTextiles medium between communication and remote charging activities. Remote charging achieves up to 96% power transfer efficiency when a basestation battery is used to charge remote ultra capacitors, which are used as the power supplies of body-worn nodes. Operating at 0.9 V and at 10 Mb/s, the receiver and transmitter front-ends together consume 3.2 pJ/bit over 1 m, which is at least 20X more efficient than conventional BAN receiver front-ends. The transceiver also contains an integrated digital baseband and medium access controller, which, together with the receiver front-end, consume 110 \muW during continuous operation. [ABSTRACT FROM AUTHOR]

A low power wireless transceiver has been presented for near-field data transmission across inductive telemetry links, which operates based on pulse harmonic modulation (PHM). This PHM transceiver uses on-off keying (OOK) of a pattern of pulses to suppress inter-symbol interference (ISI), and its characteristics are suitable for low-power high-bandwidth telemetry in implantable neuroprosthetic devices. To transmit each bit across a pair of high-Q LC-tank circuits, the PHM transmitter generates a string of narrow pulses with specific amplitudes and timing. Each pulse generates a decaying oscillation at the harmonic frequency that the receiver LC-tank is tuned at, which is then superimposed with other oscillations across the receiver at the same frequency, to minimize the ISI. This allows for reaching high data rates without reducing the inductive link quality factor (to extend its bandwidth), which significantly improves the range and selectivity of the link. The PHM receiver architecture is based on non-coherent energy detection with programmable bandwidth and adjustable gain. The PHM transceiver was fabricated in a 0.5-\mum standard CMOS process, occupying 1.8 mm^2. The transceiver achieved a measured 10.2 Mbps data rate with a bit error rate (BER) of 6.3\times 10^-8 at 1 cm distance using planar implant sized (1 cm^2) figure-8 coils. The PHM transmitter power consumption was 345 pJ/bit and 8.85 pJ/bit at 1 cm and zero link distances, respectively. The receiver dissipates 3 mW at 3.3 V supply voltage. [ABSTRACT FROM AUTHOR]

Carrierless impulse radio ultra-wideband (IR-UWB) radios have attracted significant research interest due to their low system complexity and power consumption. Unfortunately, IR-UWB systems suffer from the difficulty in controlling the transmitted spectral mask because of process, voltage, and temperature variations. In this paper, a monolithic 3–5-GHz IR-UWB transceiver is presented that integrates both amplitude and spectrum tunability, thereby providing adaptable spectral characteristics for different data rate transmission. The noncoherent receiver employs a simplified low-power merged correlator, eliminating the need for a conventional sample-and-hold circuit. After self-correlation, the demodulated data is digitally synchronized with the baseband clock. The 4 \ mm^2 0.13 \mu\ m CMOS transmitter and receiver consume 2.2 and 13.2 mW, respectively at the data rate of 100 Mb/s. The measured peak-to-peak transmitted pulse amplitudes are 240, 170, and 115 mV, with a tunable frequency range of 3.2–4.1 GHz. The receiver exhibits a maximum gain of 70 dB, noise figure of 8.6 dB, and the input 1-dB compression point of -\28 dBm. With off-chip antennas, the transceiver achieves a bit error rate of \10^-3 at a sensitivity of -\50 dBm. [ABSTRACT FROM AUTHOR]

An experimental verification of energy link loss between the source at the transmitting antenna and the load at the receiver for ultrawideband systems is presented. The proposed closed-form approximations for the link loss analysis are verified experimentally for different types of antennas and pulse excitations. The measurements showed that the shape of the received pulse depends on the antenna transfer functions and the received pulse energy depends on effective height of the antenna. [ABSTRACT FROM PUBLISHER]

Autocorrelation receiver (AcR) is usually used as the general receiver for transmitted reference (TR) communication systems on a quite intuitive basis. In this paper, we apply the principle of statistical invariance to obtain the optimum TR receiver on a decision-theoretic basis, and it is shown that the autocorrelation receiver is optimal only in a special case. Performance of the optimum receiver and the suboptimum AcR for some important modulation schemes is also evaluated. The results imply that allocating a part of the transmitted energy and bandwidth to reference pulses would not help improve the performance of the system and the optimal performance might be achieved via much simpler non-TR transceiver structures. However, it is shown that differential TR and some other generalizations might be used to boost the performance, and numerical results are provided to assess the degree of performance improvement achieved in each case. [ABSTRACT FROM AUTHOR]

Channel estimation at the receiver side is essential to adaptive modulation schemes, prohibiting low complexity systems from using variable rate and/or variable power transmissions. Towards providing a solution to this problem, we introduce a variable-rate (VR) M-PSK modulation scheme, for communications over fading channels, in the absence of channel gain estimation at the receiver. The choice of the constellation size is based on the signal-plus-noise (S+N) sampling value rather than on the signal-to-noise ratio (S/N). It is analytically shown that S+N can serve as an attractive simpler criterion, alternative to S/N, for determining the modulation order in VR systems. In this way, low complexity transceivers can use VR transmissions in order to increase their spectral efficiency under an error performance constraint. As an application, we utilize the proposed VR modulation scheme in equal gain combining (EGC) diversity receivers. [ABSTRACT FROM AUTHOR]

In this paper, a multiband wideband code-division multiple access/high-speed downlink packet access direct-conversion receiver to cover all six Third-Generation Partnership Project bands is implemented in a 0.13-µm CMOS process. To reduce the increase of chip size due to implementation of the multimode multiband RF transceiver integrated circuit, a new integrated inductor structure sharing an inner diameter, a proposed mixed-type dc offset correction circuit, and a stacked structure of metal-insulator-metal and MOS capacitors is proposed. These silicon area reducing techniques can decrease the chip size by up to 30%. The measured full-path receiver performance is a noise figure of >3 dB, third-order intermodulation intercept point of > -17 dBm, and second-order intermodulation intercept point of > +30 dBm for all six bands. Its current consumption, including a frequency synthesizer, is 45 mA at 2.8-V supply voltage. [ABSTRACT FROM AUTHOR]