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As the complexity of software increases, the importance of software quality is ever increasing, as everyone recognizes. In order to secure software quality, various engineering methods have been proposed. However, because these methods are very specialized, the reality is that it is difficult to apply them to a distributed and small-scale development environment. So, to solve this problem, a tool to analyze the quality of source code is used. Still, it is not easy to rely on code quality in a distributed development environment. In this study, source code quality data measured in a distributed development environment is stored in a blockchain ledger based on a graph database. In this way, the reliability of code quality in a distributed development environment can be enhanced.

Herein, we report about the monolithic integration of a unique photonic stack on top of a CMOS imager using a dedicated fabrication process. The system key components consists of silicon nitride (SiNy) optical waveguides, sloped input mirror, grating in/out-couplers, and copper-based vertical mirrors defining the resonator boundaries. The stack is optimized for operation in the NIR range (800–900nm). Up to the authors' knowledge, this is the first demonstration of a fully integrated photonic stack including a sloped metal mirror combined with SiNy waveguide technology. The photonic build-up can be used for various applications among them is absorption spectroscopy as demonstrated hereafter.

In this paper, we suggest a gait training system for the foot drop patients. The intent of this system is to control electrical stimulation pattern by utilizing the plantar pressure distributions as a source of the real-time gait event detection. The design of a prototype of the ankle-foot orthosis to test this concept is described. In the future, this gait assistive system could be an alternative rehabilitation device for the foot drop patients.

LTE Network Function Virtualization (LTE-NFV) scales user services in a low cost fashion by transforming the centralized legacy LTE Core architecture to a distributed architecture. This distributed architecture makes multiple instances of LTE Network Functions (NFs) and virtualizes them on commodity data-center network. The functionality of LTE-NFV architecture breaks however, since the distributed NF instances connected via unreliable IP links delay the execution of critical events. The failure of time-critical events results in users' quality of service degradation and temporary service unavailability. In this paper, we propose a new way to virtualize LTE core network. We argue that logic-based NFs segregation should be done for NFV, instead of instance-based NFs segregation done in current NFV implementation. Our approach of ‘logic-based NFs segregation’ combines the logic of an event into a single NF, thus localizing the execution of critical events to one virtual machine. This way, only the localized entities exchange signalling messages, and the events do not experience large delays. We further reduce the delays by exploiting the parallelism in LTE network protocols; and partition these protocols such that their signalling messages run in parallel. In addition, we eliminate unnecessary messages to reduce the signalling overhead. We build our system prototype over OpenEPC LTE core network in virtualized platform. Our results show that we can reduce event execution time and signalling overhead up to 50% and 40%, respectively.

We propose a frequency reconfigurable slot dipole antenna mounted with surface PIN (S-PIN) diodes. Instead of using conventional chip-packaged PIN diodes, a plasma channels induced on the S-PIN diodes with high carrier concentrations are used to electrically change effective lengths of the slots. Thus, by turning on and off the S-PIN diodes, we can make our antenna operate in three different frequency bands. Reasonably high realized gain near at each resonant frequency confirms that the plasma channel well mimics a desired metallic property rather than absorbing RF signals. In addition, we can also estimate appropriate conductivity of the proposed S-PIN diodes by parametric study of simulations, which was not clear in conventional researches.

This work proposes a novel way to reduce overall volume of reflectarray antennas while maintaining aperture efficiency relatively high. Different from conventional approaches, a feeder antenna is placed very close to the proposed reflectarray ground plane. In order to prevent expected degradation in antenna performance, which is mainly because the feeder is very close to the reflectarray, we impose an additional condition maximizing constructive interference between direct and reflected waves. Consequently, we can show that our antenna can provide relative high antenna gain and aperture efficiency even the antenna is remarkably reduced. Excellent agreement between simulation and experiment proves the validity of our proposal.

A printed circuit board (PCB) based electrically tunable absorber (ETA) providing good absorption rate at much higher frequencies than conventional ones is proposed. In conventional ETAs, the highest absorption frequency is mainly limited by very large capacitance of commercial varactors. In order to overcome the high-frequency limit, small parasitic capacitance is intentionally introduced by narrow slits inserted in a rectangular metallic patch printed on top of a substrate. Hence, overall capacitance of the proposed ETA can be remarkably reduced according to series connection between the capacitance from the slits and varactors. Consequently, we can continuously scan absorption frequencies in any target frequency band with almost no high-frequency limitation. In addition, by changing the number of slits, we can unrestrictedly select any target absorption frequency band. Good agreement between simulation and experiment proves the validity of our approach.

The new position control scheme at the terminal time in 3-D space is proposed for mobile harbor (MH) crane system equipped with a dual-stage trolley and hoist. Wave-induced motions of the MH and container ship cause swing of the payload and time-varying target position. Since the payload being applied by resonant disturbances should be loaded or unloaded on the moving container ship with resonance frequency, it is the worst environment to perform the accurate position control. In the proposed control method, the payload is only matched to the target at the terminal time unlike the tracking control approach which makes the payload to follow the movement of target on whole time. The terminal time is defined as the moment that the target velocity is minimum to prevent damage of the container. And this method is composed of swing free control stage and positon control stage. Control schemes in each stage are model-based optimal control. To discuss the efficiency of the proposed position control, numerical simulations results and performance comparison with the previous tracking control are shown.

Statistical dialogue systems offer the potential to reduce costs by learning policies automatically on-line, but are not designed to scale to large open-domains. This paper proposes a hierarchical distributed dialogue architecture in which policies are organised in a class hierarchy aligned to an underlying knowledge graph. This allows a system to be deployed using a modest amount of data to train a small set of generic policies. As further data is collected, generic policies can be adapted to give in-domain performance. Using Gaussian process-based reinforcement learning, it is shown that within this framework generic policies can be constructed which provide acceptable user performance, and better performance than can be obtained using under-trained domain specific policies. It is also shown that as sufficient in-domain data becomes available, it is possible to seamlessly improve performance, without subjecting users to unacceptable behaviour during the adaptation period and without limiting the final performance compared to policies trained from scratch.

We propose a new method to increase both an antenna input reflection coefficient (S11) and overall efficiency of a Fabry-Perot cavity (FPC) antenna. In general, the FPC antenna consists of a partially reflective superstrate and a metal ground plane. By finding optimum arrangement of unit cells in the superstrate, we prove that we can largely widen an impedance matching bandwidth and raise overall efficiency at the same time. In addition, we also show that our method minimizes the reduction of antenna gain, which is difficult to avoid by expanding of the impedance bandwidth. All experimental results show good agreement with the prediction, which verifies the validity of our approach.

We summarize a successful method to increase reading distances of passive radio frequency identification (RF-ID) tag antennas, which is integrated with an artificial magnetic conductor (AMC) ground plane. By introducing the AMC ground plane, our tags become insensitive to target platform materials. In other words, our tags can be directly attached onto metal or dielectric materials with high permittivity with almost no degradation in their performance. In addition, using the reflection phase variation property of the AMC, we can increase a recognition distance and reduce overall height of the tag antenna, remarkably.

Statistical spoken dialogue systems based on Partially Observable Markov Decision Processes (POMDPs) have been shown to be more robust to speech recognition errors bymaintaining a belief distribution over multiple dialogue states and making policy decisions based on the entire distribution rather than the single most likely hypothesis. To date most POMDPbased systems have used generative trackers. However, concerns about modelling accuracy have created interest in discriminative methods, and recent results from the second Dialog State Tracking Challenge (DSTC2) have shown that discriminative trackers can significantly outperform generative models in terms of tracking accuracy. The aim of this paper is to investigate the extent to which these improvements translate into improved task completion rates when incorporated into a spoken dialogue system. To do this, the Recurrent Neural Network (RNN) tracker described by Henderson et al in DSTC2 was integrated into the Cambridge statistical dialogue system and compared with the existing generative Bayesian network tracker. Using a Gaussian Process (GP) based policy, the experimental results indicate that the system using the RNN tracker performs significantly better than the system with the original Bayesian network tracker.

The transverse electromagnetic (TEM) cells are widely used for field probe calibrations. We propose the verification of TEM mode with statistical method using a four-port TEM cell. The verification results are compared with Normal, Rayleigh, Gamma distribution. As a result, the 75 % quantile of the Rayleigh distribution is excellent agreement with the true quantiles for a number of calibration points.

Blind modulation classification (BMC) is one of the most important functions for modern electronic warfare. The aim of BMC is to identify the modulation type of transmitted signals by using only the samples of received signals without prior knowledge of transmitted signals. BMC algorithms can be divided into the decision-theoretic approach and the feature-based approach. The feature-based approach is more popular because of its low computational complexity. One of the disadvantages in the feature-based approach is its sensitivity to carrier frequency offset. An existing technique uses the moments of differentially processed received signals, which are robust to carrier frequency offset under AWGN channels. However, realistic channels are not typically AWGN. In this paper, we focus on the BMC techniques for aeronautical channels. We propose a blind Rician K-factor estimation algorithm in aeronautical channels, and compute the moments of differentially processed received signals with the estimated K-factor. Simulation results show that the recognition probability of the proposed algorithm improves over an existing method for aeronautical channels.

This paper presents a basic idea to connect an electromagnetic wave propagation between the air and the earth. When an electromagnetic wave escapes into the air from the earth, its refraction angle rapidly approaches 45° right after a very small incidence degree in the case of ELF wave frequency. As the wave frequency increases, the refraction angle exponentially approaches 90° which means the direction of propagation follows the earth surface. This phenomenon has an useful meaning to lessen an interference from a buried source.

The focus of this work is speech synthesis tailored to the needs of spoken dialogue systems. More specifically, the framework of HMM-based speech synthesis is utilized to train an emphatic voice that also considers dialogue context for decision tree state clustering. To achieve this, we designed and recorded a speech corpus comprising system prompts from human-computer interaction, as well as additional prompts for slot-level emphasis. This corpus, combined with a general purpose text-to-speech one, was used to train voices using a) baseline context features, b) additional emphasis features, and c) additional dialogue context features. Both emphasis and dialogue context features are extracted from the dialogue act semantic representation. The voices were evaluated in pairs for dialogue appropriateness using a preference listening test. The results show that the emphatic voice is preferred to the baseline when emphasis markup is present, while the dialogue context-sensitive voice is preferred to the plain emphatic one when no emphasis markup is present and preferable to the baseline in both cases. This demonstrates that including dialogue context features for decision tree state clustering significantly improves the quality of the synthetic voice for dialogue. © 2014 IEEE.

In this research, we suggest and implement a virtual reality system which dynamically generates the 3D stereoscopic content based on the viewing direction of the user towards a 3D screen. We propose a new approach for computing projection parameters used in OpenGL. The well-known stereoscopic rendering technique, which is called off-axis, is replaced by proposed technique that involves the changes of camera position into the process of constructing two viewing frustums for typical 3D rendering. We also introduce an approach to estimate viewer's face position in the physical screen space using inverse intrinsic matrix of digital webcam known through calibration process. Then, we extract and assign the eyes positions to virtual stereo camera positions in rendering pipeline. With the system, the real 3D perspective is achieved by using only inexpensive devices, and rendered content remains as a real physical scene with immersive dimension.

In this paper, the tracking control of mobile harbor crane at the terminal time with considering actuator saturation is proposed for accurate position control. During loading/unloading operation of mobile harbor crane in open-sea condition, it is difficult to control the container position on the desired position due to an unwanted swing motion and a continuous movement of container ship caused by external disturbances such as wave and wind. Several researches have been already studied to develop to suppress the swing motion of ship-board crane system but the tracking problem to moving target is emerging newly in ocean engineering. The tracking control system of ship-board crane should be designed although this system has complex dynamics, various external disturbances, and the limited power of actuators. In the proposed control system, constrained model predictive control(MPC) with changing input and output constraints in real-time is applied for the only terminal tracking control. The numerical simulations are performed to verify the overall terminal tracking control performances of the proposed constrained MPC.

A partially observable Markov decision process has been proposed as a dialogue model that enables robustness to speech recognition errors and automatic policy optimisation using reinforcement learning (RL). However, conventional RL algorithms require a very large number of dialogues, necessitating a user simulator. Recently, Gaussian processes have been shown to substantially speed up the optimisation, making it possible to learn directly from interaction with human users. However, early studies have been limited to very low dimensional spaces and the learning has exhibited convergence problems. Here we investigate learning from human interaction using the Bayesian Update of Dialogue State system. This dynamic Bayesian network based system has an optimisation space covering more than one hundred features, allowing a wide range of behaviours to be learned. Using an improved policy model and a more robust reward function, we show that stable learning can be achieved that significantly outperforms a simulator trained policy.

Spoken dialogue systems provide a convenient way for users to interact with a machine using only speech. However, they often rely on a rigid turn taking regime in which a voice activity detection (VAD) module is used to determine when the user is speaking and decide when is an appropriate time for the system to respond. This paper investigates replacing the VAD and discrete utterance recogniser of a conventional turn-taking system with a continuously operating recogniser that is always listening, and using the recogniser 1-best path to guide turn taking. In this way, a flexible framework for incremental dialogue management is possible. Experimental results show that it is possible to remove the VAD component and successfully use the recogniser best path to identify user speech, with more robustness to noise, potentially smaller latency times, and a reduction in overall recognition error rate compared to using the conventional approach.

This paper presents a compact GPS/BT/WiFi triple-band triple-mode RF front-end module (FEM) with Si-based embedded actives and LTCC-based embedded passives. The proposed RF FEM consists of a triplexer, baluns, matching circuits in the LTCC substrate, and a PA, an LNA, a SAW filter on the LTCC substrate. Furthermore, the proposed FEM has a silicon module on top of the LTCC substrate in which three active devices and several DC blocking capacitors are embedded using cavity structure and IPD process. The size of the proposed RF FEM is only 5.0 mm × 6.0 mm with an LTCC substrate thickness of 0.85 mm. The measured results show that in GPS path, we obtain a gain of 15.4 dB, and a noise figure of 2.2 dB at 1.575 GHz. In WiFi 2.4-GHz band, the Rx path provides a gain of 15 dB considering 3-dB power split with an amplitude imbalance of 1.2 dB and a phase difference of about 178°–182°. In WiFi 5-GHz band, the Rx path provides a gain of 8.3 dB with an amplitude imbalance of 0.8 dB and a phase difference of 177°–181°. Also, the RF FEM provides a P1dB of more than 20 dBm and sufficient adjacent channel power characteristics at both frequency bands.

Real-time rendering for massive terrain data is a challenging work. Previous GPUs are not suitable for rendering massive mesh data. Recently, with tessellation shaders and geometry shader added on a GPU, it is possible to tessellate triangles or quad patches to improve geometrical features of mesh objects. In this paper, we propose a massive terrain rendering technique in real-time using GPUs. We made displacement and normal map from massive terrain data on the GPU. As a result, we could tessellate a coarse base mesh with a high resolution texture as displacement map and normal map for shading from massive terrain data.

We present flexible, ultra-sensitive and mechanically robust H 2 S gas sensors consisting of ZnO nanowires decorated with palladium (Pd) nanoparticles (NPs) supported by a polyimide substrate. ZnO nanowires were synthesized at desired location via hydrothermal method using local thermal energy generated by microheater array, which is integrated in a device. Also, the surface of ZnO nanowires was modified with Pd NPs by local wet chemical reaction for selective and sensitive detection of H 2 S gas. The H 2 S sensing of Pd NP-coated ZnO nanowire sensors was investigated under various measurements including the sensor response/recovery time, bias voltage effects of microheater array, and mechanical loading. The sensing performances of the flexible Pd NP-coated ZnO nanowire sensors were found to be extremely sensitive, reliable and robust for the detection of H 2 S gas.

In traditional wireless networks, two nodes cannot simultaneously transmit their packets to each other with one radio device (having no machinery enabling full duplex). To ensure bidirectional communications, we need a medium access protocol to coordinate neighboring nodes' transmissions. Two conflicting design goals for the medium access protocol are the ease of implementation and performance guarantees. We propose a novel medium access protocol which is easily implementable (not requiring clock synchronization) and guarantees performance (the fraction of available slots). Our basic idea is to exploit a set of binary sequences having provably low cross-correlation. Each node has its own code sequence and determines whether to transmit or receive a packet by sequentially examining each bit of the code sequence. As an example, we consider the application of Gold code sequences and theoretically analyze the the fraction of available slots that a Gold-code- based MAC can provide. Our simulation verifies our analysis and shows that a Gold-code-based MAC guarantees the fraction of available slots even on a short time scale.

In high concentration photovoltaic (HCPV) systems, III-V multijunction solar cells work under high concentration condition at a small size, normally less than 1cm2. In this case, the metal coverage ratio and the current density become larger than those in the case of flat-plate solar cells. Due to the high current density, combined with the sheet resistance of solar cells, most of currents reverse to photocurrents flow vertically under front metal grids. This non-uniformity is critical when the metal coverage ratio is large as the case of concentrator solar cells. In this paper, the effects of metal coverage ratio and non-uniform reverse current density (i.e. forward bias current density) on the performance of InGaP/InGaAs/Ge triple-junction solar cells under high concentration were analyzed in detail. Moreover, by introducing reverse current blocking layer between metal busbar and AlInP window layer, we have successfully reduced the unwanted reverse current and achieved significant improvement in cell efficiency under high concentration condition.

P-type NiO thin films were prepared by magnetron sputtering and their characteristic properties were investigated with varying oxygen gas ratio in sputtering ambient. From the measurements of Hall effect and Seebeck coefficient, the films were confirmed to be of p-type conduction. NiO films were applied as the anode buffer layer between ITO and active layer in organic solar cells. Effects of the buffer NiO film on the device performance were systematically studied in this work.

Palladium (Pd) nanotube array was fabricated by a facile solution process using hydrothermally synthesized ZnO nanowires as sacrificial templates and Pd precursor solution. The morphology, structure, and composition of the nanotubes were characterized by SEM, TEM, HAADF-STEM, and ICP-ACS, respectively. To investigate hydrogen sensing performance, Pd nanotube arrays were fabricated on interdigitated electrodes of a silicon chip and the electrical resistance change of Pd nanotube array sensor was measured depending on the concentration of hydrogen gas and operating temperature. Pd nanotube arrays sensor was also fabricated on polymer substrate by the same method and exhibited a good hydrogen detection performance.

Highly efficient and simple process to fabricate ZnO nanowire-based gas sensing devices was developed. ZnO nanowires (NWs) were locally synthesized by hydrothermal method using localized thermal energy, which is generated by microheater arrays integrated in the device. To enhance the sensitivity to hydrogen (H 2 ) gas of ZnO NW-based sensor, the surface of ZnO NWs was modified with Platinum (Pt) nanoparticles via local wet chemical reaction. H2 sensing performances of the intrinsic and Pt-coated ZnO NWs were compared at two operating temperatures (250°C and 350°C). We found that the sensing device based on ZnO NWs decorated with Pt nanoparticles has higher sensitivity compared with intrinsic ZnO NW sensor.

In this paper, a novel integrated Tx-Rx diplexer for dual-band Worldwide Interoperability for Microwave Access (WiMAX) application is realized by low temperature co-fired ceramic (LTCC) technology. The proposed Tx-Rx diplexer has 5 ports and consists of two lowpass filters, two bandpass filters, and one common matching network, which are fully embedded in the LTCC substrate. This novel structure can be applied for either Tx or Rx path by simply making two ports to be shorted to the ground. The fabricated Tx-Rx diplexer has 9 pattern layers including 3 ground layers and it occupies less than 3.0 mm × 2.5 mm × 0.528 mm. In case of Tx operation, the measured insertion losses at 2-GHz and 5-GHz band are less than 0.9 dB and 2.5 dB, respectively, with a return loss of more than 19.4 dB and 10 dB. Furthermore, it provides a more than 32-dB and 19.2-dB second harmonic suppression at 2-GHz and 5-GHz bands is obtained. In case of Rx operation, the insertion losses are less than 1.4 dB and 2.4 dB in 2-GHz and 5-GHz bands. It provides a more than 30-dB and 32-dB attenuation at 2-GHz and 5-GHz band. The measured results of the implemented Tx-Rx diplexer are in good agreement with the simulated results. The RF FEM was realized by the proposed Tx-Rx diplexer and 4 PIN diodes at each port except antenna port for shortening to the ground or not. It can be low-loss and low-cost solution by removing MMIC SPDT switch in series connection.

A multiband antenna with a parasitic radiator for GSM900/DCS1900/WiMax wireless communication services is proposed. The proposed antenna is small in size (40mm × 40mm × 1.6mm) with simple structure. By adjusting the electromagnetic coupling between radiators, resonant frequencies and bandwidth of the antenna are controlled and the multiple-resonant operations are achieved. Parametric analysis has been conducted to investigate the effect of several important parameters of the antenna. The measured results of the prototype are discussed.

In this work, we have proposed a novel voltage controlled spatial modulation method for a digital microshutter display. A single pixel is composed of multiple sub-microshutters with the same characteristics. And the grayscale level of it is modulated by the number of actuated sub-microshutters controlled by applied voltage distribution in floating counter electrodes and hysteresis phenomenon in electrostatic microshutters. Through the proposed modulation method, the microshutter having low operation voltage under 20V together with large deflection of quarter circle shape has been demonstrated.

In this paper, we propose a joint precoding scheme for both the base station (BS) and relay station (RS) to increase the ergodic capacity of downlink non-regenerative multiple-input multiple-output(MIMO)-relay systems. Different from previous work, we assume only the mean and the covariance matrix are known for the channel state information (CSI) of the RS-mobile station(MS) link. Since the exact solution of this problem is difficult to be found because the RS-MS channel is only partially known, we employ precoding matrices that maximize the upper bound on the ergodic capacity. Based on this approach, the proposed scheme uses an iterative method to determine both BS and RS precoding matrices simultaneously. In numerical results, the proposed joint precoding scheme is shown to outperform the water-filling and amplify-and-forward (WF-AF) scheme in high signal-to-noise ratio (SNR) regions. It is also shown to outperform the spatial multiplexing and RS precoding (SM-RP) scheme in low SNR regions.

Recently, medical advances have been increasing the size of the aged population. With rapidly developing technology, computers are now essential parts in our daily life, and the number of the aged people using computers is also increasing continuously. But user interfaces and contents for the aged people have not yet been developed actively. In this paper, we present a 3D sensory gate-ball game which can be played by the aged people easily. This study is based on 3D graphics and uses a realistic gate-ball stick and balls as interfaces, so it can improve both physical and mental health of the aged people. Because our game is a sensory game, it is easy to play in house without an outdoor playground. In addition, the game provides many interesting situations so that it can raise the participation and interest of the aged people.

We have investigated the perturbed electronic states and energy relaxation dynamics of phenylene bridged zinc(II) porphyrin dimers to reveal the effects of phenylene bridges by using computational and time-resolved spectroscopic methods. We can gain further insight into the dipole-dipole interactions and through-bond/through-space electronic exchange ones between the neighboring porphyrin moieties.

In this paper, as one of those RFID tags, novel RFID tag antennas mountable on metallic objects using EBG surface for passive UHF/RFID applications. These tags achieve longer read ranges than tags using EBG surface, and can be utilized in various retail store products including metal, motor vehicles, and containers, etc. Details of the serial design and analysis of the proposed tag are described and the experimental results of the constructed prototype are presented.

As the distance between terminals in modern wireless networks tends to decrease, the energy consumption issue, conventionally assumed to be exclusively dominated by the transmission power, needs to be revaluated. In particular, retransmission (ARQ) protocols that typically reduce the transmission energy required to obtain a given error probability on the channel (at the expense of a larger delay), also increase the energy consumed by the circuitry other than the power amplifier. In this paper, the energy efficiency of hybrid-ARQ type I, chase combining and incremental redundancy protocols in Rayleigh fading channels, is analyzed by accounting for the energy consumed by the transmitting and receiving electronic circuitry. It is shown that the advantages of hybrid-ARQ protocols in terms of energy consumption strictly depend on the transmission range.

The paper describes our recent work on improving broadcast news transcription and presents details of the CU-HTK broadcast news English (BN-E) transcription system for the DARPA/NIST rich transcription 2004 speech-to-text (RT04) evaluation. A key focus has been building a system using an order of magnitude more acoustic training data than we have previously attempted. We have also investigated a range of techniques to improve both minimum phone error (MPE) training and the efficient creation of MPE-based narrow-band models. The paper describes two alternative system structures that run in under 10/spl times/RT and a further system that runs in less than 1/spl times/RT. This final system gives lower word error rates than our 2003 system that ran in 10/spl times/RT.

This paper discusses the development of the CU-HTK Mandarin Broadcast News (BN) transcription system. The Mandarin BN task includes a significant amount of English data. Hence techniques have been investigated to allow the same system to handle both Mandarin and English by augmenting the Mandarin training sets with English acoustic and language model training data. A range of acoustic models were built including models based on Gaussianised features, speaker adaptive training and feature-space MPE. A multi-branch system architecture is described in which multiple acoustic model types, alternate phone sets and segmentations can be used in a system combination framework to generate the final output. The final system shows state-of-the-art performance over a range of test sets.

We propose a multiple input multiple output single carrier direct-sequence code division multiple access (MIMO SC-DS-CDMA) transmission scheme of high speed broadband communication over time varying frequency selective Rayleigh fading channels. The system is used in conjunction with Hybrid Automatic Repeat reQuest (HARQ) to provide better BER performance and throughput. Furthermore, the proposed scheme employs both Time domain and Frequency domain spreading in contrast to other CDMA system which employs only Time domain spreading. The frequency domain spreading provides frequency diversity that improves the performance of the system. BER performance of the scheme is studied and the results are presented.