A novel auditory feature that combines an auditory model and music theory is proposed for audio fingerprinting. First, the input audio is filtered by a GammaChirp (GC) filterbank to model the cochlear frequency selectivity. Then, the output of the filterbank is down-sampled and decorrelated by a discrete cosine transform to obtain the GammaChirp frequency cepstral coefficients (GCFCCs). Next, some lowest order GCFCCs are projected onto the chroma to characterise both melodic and harmonic information of the input. Finally, non-negative matrix factorisation is applied to the chroma matrix to reduce its dimension while maintaining its discriminative power. The experimental results illustrate that the proposed scheme achieves a stabler identification rate and lower computational complexity than the schemes based on the Mel-frequency cepstral coefficients.

A vertically multilayered Yagi antenna is presented. The antenna consists of a novel dual-element folded dipole, three latticed director arrays and a ground plane. The dual-element folded dipole is composed of a pair of folded dipoles which are fed by an internal feedline. It mainly makes the proposed Yagi have a bandwidth of 70.8% (1.34–2.83 GHz) for a return loss (RL) > 10 dB. The latticed director arrays and the ground plane are utilised to enhance the gain performance of the multilayered Yagi antenna. The measured and the simulated results indicate that a gain better than 10.8 dB and a front-to-back ratio (FBR) higher than 20 dB can be obtained in the frequency range 1.7–2.83 GHz which covers the second generation 2G/3G/long-term evaluation (LTE) application.

A broadband, miniaturised bow-tie antenna array element designed to be used in three-dimensional (3D) microwave imaging systems based on the tomographic approach is proposed. Miniaturisation is achieved by adding inductive strips to the capacitive antenna element and thereby lowering the cutoff operational frequency. Furthermore, the broadband directive radiation characteristic of the antenna with the proposed feeding network is equivalent to that of the same antenna being fed by an ideally symmetrical feeding network. This characteristic assists in the modelling of the antenna in the numerical solver. The proposed broadband antenna covering 0.85–3.25 GHz is a compact, directive element with a simple structure having the potential to be implemented in the numerical solver in 3D microwave tomography without imposing a high computational cost on the solver.

Medical diagnostic systems demand wideband antennas with directive radiation patterns. In addition, portable systems require low profile and light weight antennas to be incorporated. These necessities of modern microwave-based diagnostic systems are addressed in this reported work. The antenna is built with two simple thoroughly printed structures connected to each other using two copper walls, forming a loop-like geometry. The top element is capacitively loaded with a pair of symmetrically placed slots and fed with a coplanar waveguide (CPW). The antenna works like a small loop in the lower resonating mode and as a folded-dipole in the higher modes. The antenna exhibits a 109% bandwidth with stable radiation patterns of an about 9 dB front-to-back ratio over most of the band with only a profile of 0.05λ (λ = wavelength at the lowest frequency). The measured and the simulated results show that the proposed antenna is suitable for wideband medical imaging systems.

A novel dual-band multiple-input multiple-output (MIMO) antenna system with diversity polarisation and high port isolation is proposed. The antenna system consists of six antennas (three antennas operate at 2.44 GHz and the others at 5.25 GHz) mounted on a hexagon ground plane and backed by a centrally located hexahedron. The antennas for different bands are arranged in an alternative fashion along the peripheral of the hexagonal ground. From simulation and experimental results, the proposed MIMO system has been shown to perform superbly at both the 2.44 and 5.25 GHz bands, with significant and consistent improvements in sidelobe levels and envelope correlation coefficients at the lower band due to the presence of the hexahedron.

A compact universal serial bus (USB) antenna design for wireless USB dongle application is presented. The use of the theory of characteristic modes (CMs) to design such an antenna is novel and leads to a systematic antenna design scheme. The physical insight that the CM offers is of great importance for designing such an antenna. The systematic placing of reactive loads on the antenna body plays a key role in matching the antenna at the desired frequency bands. The proposed antenna's overall size is (48 × 10 mm) and it can serve the WLAN IEEE 802.11 a/b/g/n bands (2.4/5.5 GHz). It could also be used for the Bluetooth and LTE applications.

At the C-band, a double-layer series-fed linear array antenna is proposed. T-shape and interdigital microstrip transmission lines are used to increase the impedance bandwidth and obtain a reduced sidelobe level (SLL). The antenna has a bandwidth (BW) of 28% (VSWR ≤ 2), a SLL of −20 dB and a gain of 13.5 dB across the BW of 23%. Details of the antenna design and the experimental results are presented.

A wideband omnidirectional vertical polarised antenna is presented. By incorporating a shorted coupling top loading structure over two cross-connected monopole antennas, an enhanced impedance bandwidth of 152% is achieved. The prototype antenna operates from 650 to 4500 MHz, with a reflection coefficient <−15 dB, a 2–6 dBi antenna gain with a very stable vertical radiation pattern and <3.5 dB horizontal pattern ripples. The proposed antenna can be widely used in indoor distributed antenna systems (DASs), such as GSM900, GSM1800, UMTS2100 and the enhanced TD-LTE (up to 3.5 GHz) bands. The simulated and the measured return loss and radiation pattern results show good agreement.

Microwave tomography (MWT) is exploited for the detection of haemorrhagic stroke by using a nonlinear iterative imaging algorithm. An anatomically realistic two-dimensional (2D) head model is simulated using a finite difference time-domain numerical solver. By using an iterative optimisation algorithm based on the Gauss–Newton approach, the head model with an artificially embedded stroke region modelled as blood is successfully reconstructed through a blind reconstruction procedure (i.e. no a priori information about the shape or the dielectric properties of the model is assumed). It is observed that beginning from a homogeneous guess similar to the background material, right after the first iteration the shapes of the layers are clearly distinguished and the values of the dielectric properties converge to the actual values after only 10 iterations.

A five-transistor dynamic ternary content addressable memory (CAM) is presented for high-density data search applications. The data path and the search path are separated to avoid unwanted capacitive coupling at the storage node. To increase the data retention time, the data lines are grounded and dummy search lines are implemented for refresh operations. The proposed CAM cell is fabricated using a 130 nm CMOS process, and occupies an area of 8.99 μm². A prototype array of 64 × 128 search memory has a retention time of 2.84 ms at room temperature with a 1.2 V supply voltage. The hardware search performance is compared with a conventional software-based search scheme, running on two different systems with clock frequencies of more than an order of magnitude faster. The hardware search engine exhibits comparable search speeds while dissipating only 149 mW.

A switching architecture for exponential function generators in submicron CMOS technology is proposed. The architecture is based on second-order rational approximation of exponential functions and can be realised using MOS transistors in the saturation regime. An implementation eliminating complex squarer/multiplier circuits is presented in 0.13 μm CMOS technology. Simulation results show a dB-linear range of 46 dB with less than ± 0.5 dB linear error while dissipating a maximum of 0.45 mW from a 1.2 V power supply.

Impedance spectroscopy, a technique for analysing electroceramics, is applied to the two-port form of the Cauer network which is commonly used as a thermal circuit analogue. The transfer impedance spectra of the Cauer network representations of a single material are presented as Nyquist plots for a range of network orders. The results demonstrate that a model with four or more resistor-capacitor elements is required to accurately model a single material. The effect of taking a measurement at different points within a single material is then reported and four elements are similarly required between the heat source and the measurement. The existing modelling techniques, which often use only one element per material block, are shown to be especially inaccurate. By using these findings, a design engineer can produce a better thermal model of a complete system by making an informed compromise between the model's accuracy and complexity.

The resistive switching behaviour observed in microscale memristors based on laser ablated ZnO and VO₂ is reported. A comparison between the two materials is reported against an active device size. The results show that devices up to 300 × 300 μm² exhibit a memristive behaviour regardless of the device size, and 100 × 100 μm² ZnO-based memristors have the best resistance off/on ratio.

A stochastic modelling method is developed and implemented in a SPICE framework to analyse variability effects on interconnect structures including general nonlinear elements.

An efficient method is introduced for detecting humans in surveillance video. The method improves the performance of multiscale human detection through the use of a scalemap, and does not require knowledge of the camera parameters or the use of additional devices. A scalemap is a map that links each position in the observed image to the optimal detection scale. The proposed method efficiently reduces the computational costs by estimating the scale of interest and the region of interest based on the scalemap, while maintaining the accuracy of the detection. It is experimentally shown through an experiment that the proposed method can improve both the accuracy and the efficiency of real-world surveillance videos.

Fingerprint encryption in embedded environments should satisfy both lightweightedness and secureness. Normally, the encryption scheme divides the 8-bit pixel images into bit planes and then performs full encryption for one bit plane, e.g. least significant bit plane, and simple operations for the remaining bit planes. Thus, the scheme performs better compared with the 8-bit full encryption, while the security is decreased since only one bit plane is fully encrypted. An innovative fingerprint encryption scheme is proposed which supports better security while maintaining the overall performance. The proposed scheme uses a bit plane encryption and a random block feedback. The encryption schemes are implemented and tested with 320 sample fingerprint images. The result shows that the scheme has superior aspects compared with the existing bit plane encryption and even with the naive full encryption.

A direct method for recovering three-dimensional (3D) head motion parameters from a sequence of range images acquired by Kinect sensors is presented. Based on the range images, a new version of the optical flow constraint equation is derived, which can be used to directly estimate 3D motion parameters without any need of imposing other constraints. Since all calculations with the new constraint equation are based on the range images, Z(x, y, t), the existing techniques and experiences developed and accumulated on the topic of motion from optical flow can be directly applied simply by treating the range images as normal intensity images I(x, y, t). In this reported work, it is demonstrated how to employ the new optical flow constraint equation to recover the 3D motion of a moving head from the sequences of range images, and furthermore, how to use an old trick to handle the case when the optical flow is large. It is shown, in the end, that the performance of the proposed approach is comparable with that of some of the state-of-the-art approaches that use range data to recover 3D motion parameters.

Given a dataset of two-dimensional points in the plane with integer coordinates, the method proposed reduces a set of n points down to a set of s points s ≤ n, such that the convex hull on the set of s points is the same as the convex hull of the original set of n points. The method is O(n). It helps any convex hull algorithm run faster. The empirical analysis of a practical case shows a percentage reduction in points of over 98%, that is reflected as a faster computation with a speedup factor of at least 4.

Existing point-of-interest (POI) descriptions are biased by the information surrounding the point. Whereas in self-contained images this information is useful for enhancing the repeatability of the description, its use is inadequate for the description of objects that might be surrounded by variable backgrounds. To tackle these situations, a new POI descriptor – super-pixel-based isolation of the scale invariant feature transform (SP-SIFT) – is proposed. The classical SIFT descriptor is modified by isolating the information of the flat areas that compose it. It is proposed to include superpixel information in the description stage of the SIFT. The obtained results suggest that a so-built descriptor increases the repeatability of SIFT points in these scenarios while keeping its robustness to global transformations of the image: blurring, changes in viewpoint, scale and lighting. The method is presented here as an extension of the SIFT. However, the idea behind it may be easily exported to most of the existing POI-descriptors in the state-of-the-art.

A structure tensor based in-loop filter to remove the compression artefacts in depth video coding is proposed. Instead of involving all neighbouring depth pixels in the joint filtering process, the algorithm chooses one neighbouring depth pixel as the filter output from a reliable neighbour region which is adaptively determined by a structure tensor analysis. It can effectively reduce the negative influence of the non-similar neighbouring depth pixels and improve the quality of the synthesised virtual views. The experimental results show that the proposal is more effective in improving the depth video coding efficiency.

A novel two-layer motion estimation which searches motion vectors on two layers with partial distortion measures in order to reduce the overwhelming computational complexity of motion estimation (ME) in video coding is proposed. A layer is an image which is derived from the reference frame such that the summation of a block of pixels in the reference frame determines the point of a layer. It has been noted on different video sequences that many motion vectors on the layers are the same as those searched on the reference frame. Experimental results on a wide variety of video sequences show that the proposed algorithm achieves both fast speed and good motion prediction quality when compared with the state-of-the-art fast block matching algorithms.

A novel check-node lazy scheduling (CLS) approach is presented for the layered belief propagation (LBP) decoding algorithm in low-density parity-check (LDPC) applications. In the cases where the check nodes are highly reliable, this proposed CLS approach skips the check nodes in the belief propagation processes, and thus it clearly reduces the iteration times of LDPC decoding. Simulations show that, when this CLS approach is integrated into the classical LBP decoding algorithm, the needed maximum iterations is improved by nearly 30%.

In the European Telecommunication Standards Institute (ETSI) framework, the vehicle-to-vehicle (V2V) and the vehicle-to-roadside (V2R) communications on the 5 GHz frequency band must use the decentralised congestion control (DCC) algorithm standardised by the ETSI. The DCC algorithm distinguishes itself from other methods in that it simultaneously regulates no less than four parameters that all work to the identical effects. However, it is have claimed that this apparently reassuring feature is actually excessive and can lead DCC to perform sub-optimally. It is shown that it could be simplified to use fewer parameters by demonstrating that a physical layer data rate control, which is only one of the four used by the DCC, achieves a better result.

A novel concept of a physical obfuscation of cryptographic keys is introduced which basically utilises identification of the metastable behaviour of field programmable gate array (FPGA) flip-flops, i.e. the time variability of the metastability's appearance. Clock and data intervals leading to metastability ( δ ) are measured with the use of programmable delay lines available in digital clock managers (DCMs). The DCM acts as a variable clock phase regulator, whereas another circuit detects metastable events. The parts of binary words representing δ become segments of a physical unclonable function key. Preliminary results show significant differences in interval δ values when a slight change in circuit implementation occurs (in placement, node connections, surrounding sub-circuits etc.). Similar FPGA devices manufactured in the same process having an identical structure also behave significantly differently due to the intrinsic inter-class randomness.

Noncommensurate sampling is an effective solution for improving the tracking performance of digital code tracking loops. So far there has been a lack of a generalised method for designing the parameters of this sampling scenario. A simple approach to choosing the parameters of noncommensurate sampling is presented, which is based on the analysis of the quantitative relationship among the chip phase delay discrimination, the sampling ratio and the correlation length. Numerical and simulation results show that optimal phase delay discrimination and thereby superior tracking accuracy can be achieved with the proposed approach. This approach is especially suitable for precision ranging applications, and can be extended to other applications involving accurate signal tracking in digital equipment.

Network virtualisation is organised as a fundamental technology for eradicating the ossified architecture of the Internet. Virtual network embedding (VNE) instantiates virtual networks on a substrate network to carry as many services as possible, which is an optimisation problem. VNE with discrete particle swarm optimisation (DPSO) is proposed, which models VNE and abstracts its constraints, modifies PSO into DPSO, adapts the characters of VNE and obtains the optimal solution to map virtual networks onto a substrate network.

A novel coupled-line stub is proposed for the design of a novel dual-band small-size bandstop filter (BSF). This kind of coupled-line dual-band BSF features a compact and simple structure, flexible frequency-ratio adjustment and high selectivity. To verify the proposed circuit structure and design approach, a microstrip example has been fabricated and measured. The measured results show a good agreement with the simulated responses.

A broadband and high-K monolithic passive balun for silicon-based radio frequency integrated circuits (RFICs) are presented. It utilises the top level thick Cu metal and adopts a 16-side geometry. The proposed balun is designed and fabricated with a 0.13-μm CMOS mixed-signal 1P6M process. The measured results show that the amplitude imbalance is < 0.2 dB and the phase imbalance is within 4° from the frequency range of 0.1–7 GHz. Compared with the typical octagonal balun, the proposed design achieves the same coupling coefficients K and attains an enhancement in the transmission efficiency S ₂₁ within the frequency range of 0.1–20 GHz, and the consumed chip area is reduced by 3%.

A negative-order resonator (NOR) based on a ridge substrate integrated waveguide (RSIW) structure and its application to a coupled-resonator filter (CRF) is investigated. The NOR is realised by etching an interdigital slot on the ridge surface of the original RSIW to achieve the composite right/left-handed (CRLH) characteristics, which makes the resonator exhibit the unique property of negative-order resonances. The −1st-order resonance can be generated with a much lower resonant frequency than that of the original RSIW resonator with the same size. Thus, miniaturisation can be achieved by using this NOR structure. Besides, the non-radiative property of the CRLH RSIW structure would help in avoiding radiation loss and electromagnetic interference to the other circuits, which is a better choice in guided-wave applications than other open radiative CRLH structures. Electric coupling is adopted between the neighbouring resonators in the filter design. This CRF shows the advantages of a low-profile, compact size, non-radiation as well as easy integration with other planar circuits.

A novel broadband microwave absorber design concept using a honeycomb sandwich structure is proposed. Unlike the conventional microwave absorbing honeycomb sandwich structure, the newly proposed design concept uses the transverse direction of a honeycomb structure with a coated lossy material. When the incident waves reach the inside of the honeycomb coated with the lossy material, multiple scattering occurs inside the honeycomb due to the two different refractive indices. Then, the trapped electromagnetic (EM) waves lose energy due to the coated lossy walls. Thus, the honeycomb structure can be used in the transverse direction and the effective thickness in terms of the incident EM waves becomes very large. This considerable thickness represents a very effective way to sufficiently attenuate the trapped waves. This way, a lightweight and broadband absorber could be implemented without use of a magnetic material and without any limitations on the thickness.

The phase noise and frequency stability measurements of 1 GHz, 100 MHz and 10 MHz signals are presented which have been synthesised from the 11.2 GHz outputs of two nominally identical independent cryogenic microwave sapphire oscillators.

An ultra-wideband double-balanced resistive mixer with high dynamic range (IIP3) is reported. The mixer is designed and fabricated using HRL Laboratory's GaN high electron mobility transistor (HEMT) (T2) process and it utilises a series resistor-capacitor circuit network termination to the device gate, in order to achieve resonance-free broadband conversion loss and high dynamic range. The measured conversion loss from 3 to 40 GHz is between 5.5 and 8.5 dB at 1 GHz intermediate frequency. Large signal testing at 15 GHz showed a 1 dB gain compression point (P _{1 dB}) of 22 dBm.

A vector network analyser is used to study the electrical properties of multi-walled carbon nanotube (MWCNT) thin films deposited on a fused quartz substrate in the sub-terahertz (THz) frequency ranges of 220–325 GHz (WR3.4) and 325–500 GHz (WR2.2). The experiment is performed in free space. The complex permittivity of the MWCNT thin films is extracted using the Nicholson-Ross-Weir method. The refractive index and conductivity are then determined from the extracted permittivity. The method is validated by comparison with values obtained using THz time-domain spectroscopy.

The first 25 Gbaud/s four-level pulse amplitude modulation (PAM) of a 1.3 μm directly modulated laser (DML) is achieved and a 10 km transmission over a single-mode fibre (SMF) with clear eye openings is demonstrated.

Owing to the limited cell size of eNodeB (eNB), the relay node has emerged as an attractive solution for the long-term evolution (LTE) system. The nonlinear limit of the alternative method to multiple-input and multiple-output (MIMO) based on frequency division multiplexing (FDM) for orthogonal FDM (OFDM) is analysed over varying transmission spans. In this reported work, it is shown that the degradation pattern over the linear, intermixing and nonlinear propagation regions is consistent for the 2 and the 2.6 GHz bands. The proposed bands experienced a linear increase in the error vector magnitude (EVM) for both the linear and the nonlinear regions proportional to the increasing transmission spans. In addition, an optical launch power between −2 and 2 dBm achieved a significantly lower EVM than the LTE limit of 8% for the 10–60 km spans.

A multilayer, low-parasitic interconnection scheme for highly scaled GaN high electron mobility transistors is reported. The fabrication process offers three Au interconnects embedded in benzocyclobutene (BCB) dielectric, with an integrated air-box in the active area in order to minimise the gate parasitic capacitances. With the addition of the air-box, it is demonstrated that the performance of the BCB encapsulated device is similar to that of a non-encapsulated device. Furthermore, by utilising the multilayer interconnection scheme a low-loss (0.75 dB) 3 dB tandem coupler operating from 140 to 220 GHz is demonstrated.

The results presented show that a simple microstructure involving a plate supported by two tethers can exhibit varied dynamics due to its nonlinearities. The plate vibrates such that the tethers experience a torsional twisting and it is designed within the constraints imposed by the MetalMUMPs process. Each region of operation has different applications and one can traverse through these regions by adjusting the sensing and actuation voltages. As one would expect, the nonlinearities dominate at higher voltages, with the first signs of chaotic trajectories appearing at 75 V. Parameters of the nonlinear model are first determined from finite-element analysis responses, and results from subsequent numerical simulations for each region are presented.

The advantage of a laser interferometer is in the high resolution it provides, especially in extremely sensitive nanometrology. The laser interferometer plays a crucial role in ultra-precision measurement areas. However, the measurement accuracy is limited by a nonlinearity error. The nonlinearity error of the heterodyne laser interferometer needs to be compensated for. An H _∞ filter is applied to compensate for the nonlinearity error caused by the elliptic polarisation, two non-orthogonal beams and an imperfect optical alignment. The proposed compensation method using an H _∞ filter can reduce the nonlinearity error. The experimental results show an improved accuracy and reliability.

A single-pixel sensor consisting of a dual-lock-in amplifier with an innovative dual-cathode photodetector is presented. The sensor is fabricated in 0.35 µm CMOS and is designed to be integrated in a multipixel array working with a frequency shifted feedback (FSF) laser. The realised single-pixel structure occupies an area of 120 × 100 µm² at a 58% fill factor. This pixel ensures frequency detection of the optical signal independently of its phase and power. The bandwidth of the interleaved pin photodiodes is larger than 100 MHz even for 850 nm. The sensor shows a dynamic range of ∼24 dB at a modulation frequency of 10 MHz. Signals up to 35 MHz can be detected.

A method for calculating the average refractive index of a sample using transmission terahertz time-domain spectroscopy in a single measurement is presented. The refractive index is derived from the analysis of the frequency-domain interference caused by Fabry-Pérot reflections in the sample through the discrete Fourier transform of the spectrum module. This approach is simple and fast (not requiring a reference measurement), improves sensitivity over direct time-domain analysis and allows the derivation of the refractive index in a specific frequency window. The method can also be used to identify unwanted reflections in the experimental setup.

Terahertz (THz) frequency quantum cascade lasers emitting peak powers of >1 W from a single facet in the pulsed mode are demonstrated. The active region is based on a bound-to-continuum transition with a one-well injector, and is embedded into a surface-plasmon waveguide. The lasers emit at a frequency of ∼3.4 THz and have a maximum operating temperature of 123 K. The maximum measured emitted powers are ∼1.01 W at 10 K and ∼420 mW at 77 K, with no correction made to allow for the optical collection efficiency of the apparatus.

To eliminate the low-frequency oscillation phenomenon in pulse train controlled switching DC–DC converters operating in continuous conduction mode (CCM), a valley current mode pulse train control technique is proposed. The experimental results show that by using the proposed control technique, the low-frequency oscillation in the pulse train (PT) controlled CCM switching DC–DC converter can be eliminated, while the great robustness and excellent transient performance of the traditional PT control technique can be retained.

A new simple method to obtain real-time high-resolution three-dimensional (3D) images based on a static unitary detector (STUD) is reported. The STUD consists of a common bias network, a partitioned photodetector, a preamplifier array and a combiner, which makes it possible to easily increase the effective photo-detection area for a wider 3D image acquisition without affecting the ability to detect short laser pulses for high-resolution 3D images. From an implemented experimental prototype based on a STUD, the intensity and 3D images with a very high resolution (320 pixels × 240 pixels) were obtained. The achieved range resolution and the spatial resolution of remote 3D objects at 50 m were measured to be <0.3 and 1.1 cm, respectively.

300°C operation of a normally-off AlGaN/GaN metal-oxide semiconductor field-effect transistor (MOSFET) is successfully demonstrated, which is fabricated using a self-terminating gate recess etching technique. At 300°C, by employing a 15 nm-thick Al₂O₃ as the gate dielectric deposited by atomic layer deposition, the fabricated normally-off MOSFET exhibits a threshold voltage (V _th) of 3.2 V, a low off-state leakage current of ∼10⁻⁷ A/mm and a low forward gate leakage current of ∼10⁻⁷ A/mm. Thus, a high on/off current ratio of ∼ 10⁶ is obtained. Furthermore, the normally-off MOSFET also exhibits small variations in terms of its V _th from room temperature to 300°C with a maximum relative variation of 6.7% in a such temperature range. These results make this normally-off AlGaN/GaN MOSFET very promising for high-temperature digital electronics.

A new technique to realise a high-rate data transmission through electrically small antennas is presented. In this technique, the fundamental resonant frequency of a single-mode antenna is modulated by feeding the antenna with a switched capacitor with a switching signal controlled by baseband digital data. The antenna operates completely in the transient state and a DC power source is used to excite the fundamental resonances, and therefore no RF source is required.

A small metallic shield enclosure, commonly called a shield can, is an indispensable component of modern mobile devices in reducing electromagnetic interference. A sophisticated clip design utilising an embossing technique and a furrow structure for mounting shield cans on printed circuit boards in mobile devices is proposed in order to enhance the robustness and effectiveness of the shield cans. The proposed design is validated by radiated spurious emission measurement and three-dimensional field simulation.

An efficient encoding method is proposed for a class of quasi-cyclic low-density parity-check (QC-LDPC) codes with a multiple-diagonal parity-check structure. Its easy implementation with Chinese digital terrestrial/television multimedia broadcasting standard as an example is discussed. It is shown that the proposed encoder runs significantly faster and requires much fewer resources than the conventional shift-register–adder–accumulator encoder.

The symbol error rate (SER) analysis of a transmit beamforming system is investigated under delayed and limited feedback. Using the Lauricella hypergeometric series, the exact closed-form expressions of the transmit beamforming for SER with M-ary phase shift keying and quadrature amplitude modulation is derived under the delayed and limited feedback.

The detection of high data-rate wireless communication using a terahertz-frequency carrier, and a GaAs transistor as a detector, is reported. Communications are investigated around 0.2 and 0.3087 THz. For the first time, an error-free transmission at data rates up to 8.2 Gbit/s is demonstrated, using a carrier frequency of 0.3087 THz.

The use of multiple-input, multiple-output (MIMO) technology is proposed to provide unequal error protection (UEP) for layered source coding. Two priority layers are considered: a base (high priority (HP)) layer and an enhancement (low priority (LP)) layer. The MIMO is composed of two transmit antennas and two receive antennas. The HP bit stream is modulated by using four quadrature amplitude modulation (4-QAM) and the LP bit stream is modulated by using 16-QAM. The HP and the LP symbols are then coded by using a spatial–time block coding and multiplexed before transmission. The performance of the proposed system is compared with an equal error protection (EEP) system of 64-QAM and two transmit and two receive antennas. The EEP system uses spatial diversity in its MIMO to improve the decision reliability at the receiver. Both systems provide a similar capacity. The simulation results show a considerable improvement in performance for the UEP system over the EEP one.