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Создан: 13.03.2014
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Написано: 267


Photodetection unit, photodetector, and x-ray computed tomography apparatus

Суббота, 22 Марта 2014 г. 10:42 + в цитатник

Abstract:


A photodetecting unit having a favorable attaching operability is provided.

In a photodetecting unit 1, two structures for attachment 30 are fixed to the rear face of a supporting substrate 20 formed by a sintered body of a ceramic. In the process of manufacturing the photodetecting unit 1, a laminate of green sheets is fired, so as to form a sintered body of a ceramic, and then each structure for attachment 30 is bonded to the rear face of the supporting substrate 20. This allows the structures for attachment 30 to be arranged accurately on the rear face of the supporting substrate 20, thereby ameliorating the attaching operability of the photodetecting unit 1.





Description:


TECHNICAL FIELD

The present invention relates to a photodetecting unit, a photodetecting apparatus, and an x-ray tomographic apparatus which are equipped with a semiconductor substrate formed with a photodiode array.

BACKGROUND ART

An x-ray tomographic (CT: Computer Tomography) apparatus in accordance with prior art is disclosed in Patent Document 1. Taking account of defects and failures of a photodiode array and the like, the x-ray tomographic apparatus of Patent Document 1 constructs a photodetecting unit by integrating a semiconductor substrate having a photodiode array formed thereon with a ceramic substrate, and makes the photodetecting unit detachable from a base for attachment of the x-ray tomographic apparatus. This allows a maintenance operator to remove a failed photodetecting unit from the base for attachment and replace it with a new photodetecting unit.

In Patent Document 1, a semiconductor substrate smaller than the ceramic substrate is joined to the center of the front face of the ceramic substrate, while through holes penetrating through the ceramic substrate from the front face to the rear face are formed on both sides of the semiconductor substrate. The maintenance operator can attac ...

Conductive trace with reduced RF impedance resulting from the skin effect


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Wide frequency range delay locked loop

Суббота, 22 Марта 2014 г. 10:41 + в цитатник

Abstract:


A delay locked loop operates over a wide range of frequencies and has high accuracy, small silicon area usage, low power consumption and a short lock time. The DLL combines an analog domain and a digital domain. The digital domain is responsible for initial lock and operational point stability and is frozen after the lock is reached. The analog domain is responsible for normal operation after lock is reached and provides high accuracy using smaller silicon area and low power.



Description:


BACKGROUND OF THE INVENTION

Many devices such as synchronous dynamic random access memory (SDRAM) and microprocessors receive an external clock signal generated by an external clock source such as a crystal oscillator. The external clock signal received through an input pad on the device is routed to various circuits within the device through a tree of buffer circuits. The buffer tree introduces a common delay between the external clock and each buffered clock.

Typically, a delay locked loop (DLL) with an adjustable delay line is used to synchronize the buffered clock signal with the external clock signal by delaying the external clock signal applied to the buffer tree. The DLL includes a phase detector, which detects the phase difference between the external clock signal and a buffered clock signal. Based on the detected phase difference, the DLL synchronizes the buffered clock signal to the external clock signal by adding an appropriate delay to the external clock signal until the buffered external clock signal (the internal clock) is in phase with the external clock signal. The DLL can be implemented as an analog delay locked loop or a digital delay locked loop. In an analog delay locked loop, a voltage controlled delay line is used to delay the external clock signal.

FIG. 1 is a block diagram of a prior art analog delay locked loop (DLL) 100. The analog DLL 100 synchronizes an internal clock signal C ...

Metal gate compatible electrical antifuse


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Adaptive sample rate converter

Суббота, 22 Марта 2014 г. 00:51 + в цитатник

Abstract:


A sample rate converter includes a digital filter and control logic coupled to the digital filter. The digital filter is configured to receive an input data stream and to up convert the input data stream to produce an output data stream having a fixed data rate. The control logic configured to dynamically select a set of coefficients for taps in the digital filter during each clock cycle corresponding to the fixed data rate. The set of coefficients selected for each clock cycle is in accordance with a phase of the input data stream.



Description:


TECHNICAL FIELD

The disclosed embodiments relate to sample rate converters and, in particular, to sample rate converters for re-sampling data streams corresponding to digital video, digital audio and/or metadata.

BACKGROUND

Receivers in digital communications systems are often operated synchronously, i.e., the receivers perform operations on a received data stream in accordance with one or more clock signals. In some receivers, the one or more clock signals are adjusted in accordance with the received data stream. For example, a tracking loop, including a phase locked loop or a delay locked loop, in a respective receiver may be used to determine or extract transition information (such as 0 to 1 or 1 to 0) corresponding to data in the received data stream. The transition information may be used in a feedback loop to adjust a frequency of a local oscillator (such as a voltage controlled oscillator) thereby locking one or more clock signals to the received data stream and enabling synchronous operation of the respective receiver.

In other receivers, the one or more clock signals may be adjusted in accordance with an externally sourced reference time signal. For broadcast audio and/or video, for example, a broadcast studio may provide the externally sourced reference time signal. The externally sourced reference time signal may be associated w ...

eFuse containing SiGe stack


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Method and device for detecting a synchronization signal in a communication system

Суббота, 22 Марта 2014 г. 00:51 + в цитатник

Abstract:


A method and a device for detecting a synchronization signal with a high identification rate are provided, which are suitable for a wide-area Orthogonal Frequency Division Multiplexing (OFDM) system. The method and device can precisely detect information of a synchronization signal, without being interfered by transmission channels and noises in an external environment. Three sliding windows are used to obtaining a balance value as an offset value for the output signal of the method and the device. A peak position of the output signal is identified and then compensated for a delay caused by the length of one of the sliding windows. Such a position is an edge of the synchronization signal.



Description:


CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan application serial no. 96147205, filed on Dec. 11, 2007. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for detecting a synchronization signal.

2. Description of Related Art

In 1960, Orthogonal Frequency Division Multiplexing (briefly referred to as OFDM) technology using parallel data transmission and frequency division multiplexing concept has been proposed. The study about the OFDM technology mainly focuses on providing the modulation and demodulation technologies for high-speed transmission and applying to digital mobile communication systems. Inter-symbol Interference (ISI) and Inter-carrier Interference (ICI) often occur due to the errors in channel pulse response, timing synchronization, and frequency synchronization.

Therefore, in the OFDM system, one of the important tasks is timing synchronization and estimation, especially for a receiving end. Conventionally, a synchronization signal i ...

Schottky diode for high speed and radio frequency application


Timing of ultra wideband pulse generator

Суббота, 22 Марта 2014 г. 00:51 + в цитатник

Abstract:


A method and apparatus for producing timing signals for an ultra wideband pulse generator are provided. The apparatus comprises a frequency multiplier for generating a converted signal having a multiple of a pulse frequency of a reference clock signal inputted into the frequency multipliers. Furthermore, the apparatus comprises a feedback controlled delay circuitry connected to the frequency multipliers, for generating at least two versions of the converted signal, the at least two versions having a predefined delay with respect to each other, the two versions being used as timing signals for an ultra wideband pulse generator.



Description:


RELATED APPLICATIONS

This application is the U.S. National Stage of International Application No. PCT/FI2005/050169, filed 18 May 2005, published in English, and claims priority under 35 U.S.C. В§119 or 365 to Finland Application No. 20045181, filed 19 May 2004.

FIELD

The invention relates to a method of producing timing signals for an ultra wideband pulse generator using a plurality of timing signals as input, and to an apparatus for producing timing signals for an ultra wideband pulse generator using a plurality of timing signals as input.

BACKGROUND

Ultra wideband (UWB) is a promising technology for future data communications applications. UWB frequency characteristics are typically fulfilled if the fractional bandwidth Bf or the в€’10 dB bandwidth of the signal is greater than 20% or greater than 500 MHz, respectively.

A UWB system is essentially based on a base-band signal processing system, where wideband characteristics of radio transmission are obtained by generating short pulses of a typical duration of the order of nanoseconds. Based on an applied time domain-frequency domain dualism, temporal characteristics of UWB pulses directly reflect the frequency characteristics of the transmission. Therefore, high quality requirem ...

Materials, systems and methods for optoelectronic devices


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Time division synchronous orthogonal frequency division multiplexing supporting frequency division multiple access

Пятница, 21 Марта 2014 г. 17:34 + в цитатник

Abstract:


A method of time domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) communication, including the steps of: preparing OFDM-body; generating pseudo random (PN) sequence as a training signal; manipulating the PN sequence to concentrate the energy distribution thereof to the same bandwidth of sub-carriers of the OFDM-body; offsetting the manipulated PN sequence to align with frequency spectrum of the sub-carriers; and inserting the offset PN sequence as prefix of a TDS-OFDM data frame. The manipulating step may include the step of repeating the PN sequence by N times, wherein the spectrum of the repeated PN sequence concentrates on discrete bundles of sub-carriers, i.e., on one sub-carrier every N sub-carriers or M adjacent sub-carriers every MN sub-carriers, where M is an integer determined by the time duration ratio of the OFDM body and prefix. Alternatively, the manipulating step may include the step of expanding the PN sequence by N times, wherein the spectrum of the expanded PN sequence concentrates on a block of continual adjacent sub-carriers, the bandwidth of the PN sequence is 1/N of the whole bandwidth.



Description:


CROSS-REFERENCES TO RELATED APPLICATIONS

This application does not have any related US patent applications at the time of filing.

TECHNICAL FIELD

The presently claimed invention relates generally to methods and apparatus for digital multi-carrier modulation and, in particular, to methods and apparatus for Time Division Synchronous Orthogonal Frequency Division Multiplexing (TDS-OFDM).

BACKGROUND OF THE INVENTION

Orthogonal Frequency Division Multiplexing (OFDM) is one widely utilized multi-carrier based scheme for wired or wireless wideband digital communication systems. One known implementation of OFDM is by the scheme of Cyclic Prefix OFDM (CP-OFDM) in which tail part of OFDM body is used to stuff the guard interval between two con ...

Solid-state imaging device and method for manufacturing the same


Methods and systems for efficient prediction-mode selection

Пятница, 21 Марта 2014 г. 17:34 + в цитатник

Abstract:


Embodiments of the present invention comprise methods and systems for efficient prediction-mode selection.



Description:


FIELD OF THE INVENTION

Embodiments of the present invention comprise methods and systems for efficient prediction-mode selection.

BACKGROUND

In many video encoder and decoders, a picture is partitioned into fixed-size macroblocks for which the decoding process is specified. Typically each macroblock covers a picture area of 16Г—16 samples (also considered pixels) in the luma channel and 8Г—8 samples in each of the two chroma channels. Other macroblock sizes and luma to chroma ratios may be used. In some video coding standards, a picture may be split into one or several slices where a slice is a sequence of macroblocks.

In the H.264/AVC video coding standard, hereinafter H.264, luma and chroma samples of a macroblock are predicted either spatially (intra prediction) or temporally (inter prediction), and the prediction residual is encoded using transform coding. To exploit spatial correlation among pixels, H.264 defines several intra prediction modes: nine 4Г—4 intra luma prediction modes, nine 8Г—8 intra luma prediction modes (FRExt profile only), four 16Г—16 intra luma prediction modes, and four chroma prediction modes. It is desirable for the encoder to use the intra prediction mode that yields the smallest prediction cost, typically in a rate-distortion sense, among all the modes. Hence, the mode-selection process is time consuming if the encoder examines the cost of each of the intra prediction modes one-by-one.

Additionally, the H.264 standard allows intra prediction in inter coded slices. For a macroblock in an inter slice, the chance that an intra mode yields a lower prediction cost than inter prediction is very small. However, the encoder would still have to examine the cost of each of the intra prediction modes and compare them with the cost of inte ...

Electromagnetic radiation conduits


Data reproduction apparatus and method capable of determining level value of viterbi decoder, and computer-readable recording medium having recorded t

Пятница, 21 Марта 2014 г. 17:33 + в цитатник

Abstract:


A data reproduction apparatus and method to accurately determine an initial level value of a viterbi decoder regardless of whether an operating frequency is in a stable state, and a recording medium having recorded thereon a program for implementing the data reproduction method, the data reproduction apparatus including: a storage unit to store a first input signal; a frequency detection unit to generate a frequency detection signal indicating that a frequency of the first input signal is detected and frequency information of the first input signal based on a second input signal; and a level value determination unit to detect at least one level value for the first input signal by converting a sampling rate for the first input signal based on a ratio between the frequency information and preset frequency information, and to determine the detected level value as an initial level value of the viterbi decoder.



Description:


CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Application No. 2007-24207, filed on Mar. 12, 2007 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The following description relates to data reproduction using a viterbi decoder, and more particularly, to a data reproduction apparatus and method capable of accurately determining a level value of a viterbi decoder, and a computer-readable recording medium having recorded thereon a program to implement the data reproduction method.

2. Description of the Related Art

An apparatus for reproducing data from a recording medium (such as a disc) performs a binarization process to convert a radio frequency (RF) signal read from the disc into a binary signal. During the binarization process, a conventional data reproduction apparatus uses a viterbi decoder in order to obt ...

Semiconductor device, method of manufacturing the same, and signal transmitting receiving method using the semiconductor device


Interrogator

Пятница, 21 Марта 2014 г. 09:01 + в цитатник

Abstract:


A hopping pattern setting section sets, as a frequency hopping pattern code, elements of a matrix in which all integers of “1” to “the number of frequencies to be used” appear only once and which is obtained by adding, as an offset, any one of integers of “0” to “(the number of frequencies to be used)−1” to each of elements of a matrix obtained by excluding integers larger than the number of frequencies to be used from a matrix in which all integers of “1” to “(prime number larger than the number of frequencies to be used)−1” appear only once. A frequency oscillation section converts the frequency hopping pattern code into the frequencies to be used to output unmodulated signals of the frequencies to a transmission section and a reception section.



Description:


CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2006-344856, filed Dec. 21, 2006, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an interrogator which employs a scheme which perform radio communication with a responder such as a Radio Frequency Identification (RFID) tag while changing communication frequencies with time, i.e., a so-called frequency hopping scheme.

2. Description of the Related Art

In recent years, a radio communication system called a RFID system attracts attention. This system is constituted by an interrogator and a compact responder. The responder includes an IC chip and an antenna, and is generally called a RFID tag, a radio tag, an electronic tag, or the like. The interrogator performs radio communication with the responder by using an electric wave or an electromagnetic wave to write and read data in a non-contact manner. The interrogator is generally called a ...

Micromechanical device and method of manufacturing micromechanical device


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Modulated semiconductor DFB laser array with a MEMS-based RF switch

Пятница, 21 Марта 2014 г. 09:01 + в цитатник

Abstract:


Many approaches to tunable lasers use an array of DFBs, where each element of the array has a different wavelength. In some operations one element of the array is activated at a time depending on the desired wavelength. For modulated applications, an RF voltage is applied to a specific element of the DFB array, generally using an RF switch. In standard configurations, the demands on the switch are relatively difficult, generally requiring low RF insertion loss and good high frequency performance to 10 GHz. The DFB arrays are generally common cathode or common anode, depending on the type of the substrate used to fabricate the devices. Described herein is an array with a common cathode or anode configuration using a MEMS based switch that shorts the selected laser to RF ground. With this topology, preferably the off-state capacitance should be low with the MEMS switch.



Description:


BACKGROUND OF THE INVENTION

The present invention relates generally to lasers for optical communication systems, and more particularly to direct modulation of a selected laser of an array of lasers for an optical communication system.

Semiconductor lasers are used for generating the light that carries data in fiber-optic systems. The most common form of laser for long distance fiber optic communication is the distributed feedback (DFB) laser. In a DFB laser a diffraction grating is embedded in the laser and controls the wavelength of light emitted by the laser. DFB lasers can be made single mode and have narrow linewidths and excellent low noise characteristics, appropriate for fiber optic applications.

Most of the demanding long distance fiber optic links use lasers of different wavelengths, as multiple channels, each at a different wavelength, are transmitted through the fiber simultaneously. A tunable laser that can be configured for any channel is therefore very useful.

A number of configurations for t ...

Three-dimensional analog input control device


Laser system

Пятница, 21 Марта 2014 г. 09:01 + в цитатник

Abstract:


The higher efficiency and lower power consumption are realized in a laser system for generating a high-power short-pulse laser beam. The laser system includes a laser oscillator for generating a pulse laser beam by laser oscillation, plural amplifiers for sequentially inputting the pulse laser beam generated by the laser oscillator and amplifying the pulse laser beam, and a control unit for controlling the laser oscillator to perform burst oscillation and halting an amplification operation of at least one of the plural amplifiers in a burst halt period between burst oscillation periods.



Description:


BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a laser system for generating a short-pulse high-power laser beam, and specifically to a driver laser system for applying a laser beam to a target in an LPP (laser produced plasma) type EUV (extreme ultra violet) light source apparatus for generating extreme ultra violet light to be used for exposure of semiconductor wafers or the like.

2. Description of a Related Art

In recent years, as semiconductor processes become finer, photolithography has been making rapid progress to finer fabrication. In the next generation, microfabrication of 100 nm to 45 nm, further, microfabrication of 32 nm or less will be required. Accordingly, in order to fulfill the requirement for microfabrication of 32 nm or less, for example, exposure equipment is expected to be developed by combining an EUV light source generating EUV light having a wavelength of about 13 nm and reduced projection reflective optics.

As the EUV light source, there are three kinds of light sources, which include an LPP (laser produced plasma) light source using plasma generated by applying a laser beam to a target (hereinafter, also referred to as “LPP type EUV light source apparatus”), a DPP (discharge produced plasma) light sour ...

Lateral trench MOSFET having a field plate


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Method and apparatus for forward delay compensation for virtual concatenation

Пятница, 21 Марта 2014 г. 00:29 + в цитатник

Abstract:


A method and apparatus for processing member containers of a virtual concatenation group at a source side of a member container transmission network to compensate for differential delay between the member containers.



Description:


FIELD OF THE INVENTION

The invention relates to the field of network routing and, more specifically, compensation for differential delay of packets routed within a network.

BACKGROUND OF THE INVENTION

In virtual concatenation of transport containers, a group of member containers is defined over which a data stream of higher bandwidth can be transported. This is done, for example, when transporting data over SONET/SDH networks. The virtual concatenation group member containers are transported as synchronous payload envelopes across the SONET/SDH network and recombined at the virtual concatenation group receiver. These virtual concatenation groups are further enriched by a link capacity adjustment scheme, which allows dynamic provisioning and reconfiguration of virtual concatenation groups, including dynamic changes in the bandwidth of virtual concatenation groups.

In order to keep track of the member container transmission order for a virtual concatenation group, each member container has associated with it a multi-frame identifier value. At the source side of a virtual concatenation link, all member containers are assigned the same multi-frame identifier value. Since each member container is routed over a network individually, each member container experiences its own specific amount of delay caused by differences in the physical transmission path length, intermediate equipment delay, and the like. These differences in transport delay must be compensated for in order to arrange the member containers of a virtual concatenation group in the correct order at the virtual concatenation group terminating equipment.

This differential delay compensation is ...

Semiconductor device comprising gate electrode having arsenic and phosphorous


ASON/GMPLS architecture extension for reservation based and time based automatic bandwidth service

Пятница, 21 Марта 2014 г. 00:29 + в цитатник

Abstract:


A telecommunications network comprising components configured to implement a method comprising: receiving a reservation from a customer, reserving a network resource specified in the reservation, initiating the establishment of a reserved connection through a network, the reserved connection parameters based on the reservation, subsequent to the establishment of the reserved connection, detecting a data stream transmitted from the customer, and allowing the data stream to be transported over the network using the reserved connection. Also disclosed is a method for reserving bandwidth on a network, the method comprising: submitting a reservation request specifying a bandwidth requirement and a start time, receiving a confirmation that the reservation has been accepted, and transmitting a data stream to a network at the start time, wherein the data stream is transported over the network using no more than the bandwidth specified in the reservation request.



Description:


CROSS-REFERENCE TO RELATED APPLICATIONS

None.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not applicable.

BACKGROUND

Modern communication networks allow data to be transferred between electronic devices. Specifically, a source electronic device, such as a computer or a telephone, starts the transfer process by passing the data to the network. The network transports the data from the source device to a destination device, where the data may then be used as desired. The elapsed time between transmission of the data by the source device and receipt of the data by the destination device is dependent in part on the amount of bandwidth available on the network. Specifically, if there is a relatively large amount of available bandwidth, then the data may reach the destination device relatively quickly. However, if there is a relative ...

Power semiconductor device


Spanning tree root selection in a hierarchical network

Пятница, 21 Марта 2014 г. 00:29 + в цитатник

Abstract:


Communication apparatus includes a hierarchical network of switches, which includes at least a first plurality of spine switches, interconnected by a control channel, and a second plurality of edge switches having internal ports coupled to communicate via respective links with the spine switches and external ports for connecting to client devices. The spine switches are configured to detect, via the control channel, a partitioning of the hierarchical network into first and second partitions, including respective first and second numbers of the spine switches, wherein the first number is greater than the second number, and to assign respective priorities to the spine switches responsively to the first and second numbers so as to cause the larger of the partitions to be elected as a spanning tree root.



Description:


FIELD OF THE INVENTION

The present invention relates generally to communication networks, and specifically to avoidance of loops in a hierarchical communication network.

BACKGROUND OF THE INVENTION

Various types of switching networks are known in the art. Some of these types have hierarchical topologies, meaning that the switches in the network are connected together in multiple stages (or levels). A signal input at one of the edge ports of the switching network, at the bottom of the hierarchy, must pass through one or more internal stages, at higher levels in the hierarchy, before reaching another edge port from which it is output. Some hierarchical networks are non-blocking, in the sense that any unused edge port can always be connected to any other unused edge port, regardless of existing connections within the network.

A Clos network is a kind of hierarchical switching network, which is also referred to as a CBB or Fat-Tree network. This type of network topology was first formalized by Charles Clos in “A Study of Non-Blocking Switching Networks,” Bell System Te ...

Semiconductor device having a buried gate that can realize a reduction in gate-induced drain leakage (GIDL) and method for manufacturing the same


Quality of service (QoS)-aware forwarding in an MPLS network with tactical traffic engineering

Четверг, 20 Марта 2014 г. 19:06 + в цитатник

Abstract:


A router comprises an interface for receiving packets, wherein the packets include Multiprotocol Label Switching (MPLS) labels having the same label value that corresponds to an MPLS label switched path (LSP), and wherein each of the MPLS packets includes MPLS experimental (EXP) bits defined to identify a class of service to which the respective packet belongs. The router is a transit router along the MPLS LSP, and further includes a control unit that, for each of the packets, accesses forwarding information to determine whether to forward the packet along the LSP or to redirect the packet along a second LSP based on the classes of service specified in the EXP bits. The router receives policies via a user interface, and applies the policies to index into the forwarding information to select a forwarding entry, wherein the index is responsive to the label value in combination with the EXP bits.



Description:


TECHNICAL FIELD

The invention relates to computer networks and, more particularly, engineering traffic within a network.

BACKGROUND

Routing devices within a network, often referred to as routers, maintain tables of routing information that describe available routes through the network. Upon receiving an incoming packet, the router examines information within the packet and forwards the packet in accordance with the routing information. In order to maintain an accurate representation of the network, routers exchange routing information in accordance with a defined routing protocol, such as the Border Gateway Protocol (BGP).

Multi-protocol Label Switching (MPLS) is a mechanism used to engineer traffic patterns within Internet Protocol (IP) networks. By utilizing MPLS, a source device can request a path through a network, i.e., a Label Switched Path (LSP). An LSP defines a distinct path through the network to carry MPLS packets from the source device to a destination device. A shor ...

Semiconductor devices and methods of manufacture thereof


System and method for call routing based on transmission performance of a packet network

Четверг, 20 Марта 2014 г. 19:05 + в цитатник

Abstract:


A system and method that establishes a phone call over a packet network. The process may include receiving a call request from an originating call device on a packet network to call a terminating call device. A first transmission path may be determined between the originating and terminating call devices. Status of a terminating segment at a first terminating trunk may be determined and, if the status of the terminating segment at the first terminating trunk is within a first range, a call between the originating and terminating call device may be established via the first terminating call trunk. Otherwise, if the status of the terminating segment at the first terminating trunk is within a second range, a second transmission path via a second terminating trunk between the originating and terminating call devices may be made.



Description:


BACKGROUND OF THE INVENTION

Telephony has advanced dramatically with the advancement of technology. Telephone communication was once limited to an analog public switched telephone network (PSTN), where the PSTN has been traditionally formed of two types of telephone carriers, local and long distance. The local carriers established local networks for subscribers to communicate within local regions, and the long distance carriers created networks between the local networks to enable subscribers of different local carriers to communicate with one another.

Over time, mobile telephone networks were developed to enable subscribers to use mobile telephones. At first, the wireless networks and handsets were analog. Technology for the wireless networks was developed to provide digital wireless communications, which provided a clearer signal than analog wireless communications.

About the same time that the digital wireless networks were developing, the Internet was also developing. The International Standards Organization (ISO) developed an Open Systems Interconnec ...

Semiconductor device and method for fabricating the same


Method and system for transport block size signaling based on modulation type for HSDPA

Четверг, 20 Марта 2014 г. 19:05 + в цитатник

Abstract:


A device for communicating with a mobile device is provided. The devices includes a transmitter. The transmitter transmit a first modulation scheme, a first transport block size, and a first redundancy version to a mobile device. The first transport block size is represented by a first number of bits and the first redundancy version is represented by a second number of bits. The transmitter transmits a packet based on the first modulation scheme to a mobile device. transmitter transmits a second modulation scheme, a second transport block size, and a second redundancy version to the mobile device. The second transport block size is represented by a third number of bits and the second redundancy version is represented by a fourth number of bits, wherein the third number of bits is greater than the first number of bits, and the fourth number of bits is less than the second number of bits. The transmitter transmits the packet based on the second modulation scheme to the mobile device.



Description:


FIELD

The field of the disclosure relates generally to transport block size signaling, and more specifically to transport block size signaling based on modulation type.

BACKGROUND

In systems that include mobile devices, packets are generally sent using one of many modulations schemes. All packets sent during a given transfer generally conform to the same transport block size (TBS). The sender of the packets sends the receiver information telling the receiver the modulation scheme and transport block size, among other things, before the packets are sent. Therefore, once the packets are sent, the receiver knows the modulation scheme, the number of multicodes, and the transport block size of the packets and, therefore, can correctly decipher and receive the information.

Currently, much discussion has been centered around increasing the number of bits allocated for the definition of the transpo ...

Semiconductor device and method for producing the same


Method and apparatus for frequency selection at start of service session in MBMS system

Четверг, 20 Марта 2014 г. 11:42 + в цитатник

Abstract:


A method and an apparatus are disclosed for applying frequency layer convergence (FLC) to connected mode user equipments (UE) having no dedicated channel for a multimedia broadcast/multicast service (MBMS) service in a mobile communication system employing a Code Division Multiple Access (CDMA) scheme. The method and apparatus prevent uplink signaling congestion which may occur when the UEs located in non preferred frequency layers (NPL) of the MBMS service move to a preferred frequency layers (PL) when a MBMS service session starts. If the MBMS service session starts in a situation of applying the FLC, a radio network controller (RNC) notifies the UEs desiring to receive the MBMS service and located in NPLs for the MBMS service of FLC information including a PF value and a timer value, with reference to the number of the NPL UEs joining the MBMS service. The UEs performs a PF test according to the PF and timer values, thereby maintaining the degree of congestion and signal transmission load at appropriate levels.



Description:


PRIORITY

This application claims the benefit under 35 U.S.C. §119(a) of a Korean Patent Application entitled “Method and Apparatus for frequency Selection at Start of Service Session in MBMS System”, filed in the Korean Industrial Property Office on Sep. 30, 2004 and assigned Serial No. 2004-78110, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a multimedia broadcast/multicast service (MBMS). More particularly, the present invention relates to a frequency selection method and a frequency selection apparatus, which can maintain the degree of congestion of cells and the load of signal transmission at appropriate levels when a MBMS service session starts in a frequency layer convergence (FLC) situation where the MBMS service is provided in a preferred ...

Semiconductor device and method for manufacturing the same


Base station and mobile station

Четверг, 20 Марта 2014 г. 11:41 + в цитатник

Abstract:


One aspect of the present invention relates to a base station wherein either resource blocks resulting from division of a system bandwidth into blocks of consecutive frequency subcarriers or distributed type resource blocks consisting of frequency subcarriers discretely distributed within the system bandwidth and resulting from segmentation of the resource blocks into multiple resource blocks are assigned to mobile stations, the base station including: a scheduling unit configured to assign either the resource blocks or the distributed type resource blocks to the mobile stations at a predefined assignment cycle based on respective downlink reception channel states transmitted from the mobile stations.



Description:


TECHNICAL FIELD

The present invention relates to LTE (Long Term Evolution) systems and more particularly to base stations and mobile stations.

BACKGROUND ART

In fast packet scheduling where for each transmission slot or each resource block (RB) resulting from division of a frequency band of the transmission slot, transmissions are assigned to users based on reception channel states, high frequency utilization efficiency can be achieved.

In order to realize the fast packet scheduling, however, assignment information must be transmitted for each transmission slot or each resource block from a base station to user terminals, and states of transmission paths must be fed back from the user terminals to the base station, which may increase signaling overhead.

DISCLOSURE OF INVENTION

Problem to be Solved by the Invention

It may be difficult to apply the above-stated fast packet scheduling to some traffic where packets with a virtually fixed size occur at a constant cycle, such as audio services, and a severe requirement against delay is set. For such traffic, even if data is to be transmitted under an unsatisfactory reception state, it is unacceptable to w ...

Logic circuits using carbon nanotube transistors


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Mobile communication system, base station, radio network controller, and resource allocation control method used therefor

Четверг, 20 Марта 2014 г. 11:41 + в цитатник

Abstract:


A mobile communication system is provided which is capable of improving efficiency of use of allocated codes and allocated power of an HS-PDSCH to improve a throughput of the HS-PDSCH. A resource allocation update unit is connected to an RNC functional unit and a base station functional unit, performs allocation control of resources such as the number of codes and power, which are allocated or notified from the RNC functional unit to the base station functional unit, and stores allocation information of the resources in a resource allocation information storage unit. A resource use information detection unit detects a state of use of resources on the basis of a state of use of resources from the base station functional unit and a timing information from a timer, and informs a resource allocation judgment unit of the information on a state of use of resources. The resource allocation judgment unit judges whether or not allocation of resources has been updated on the basis of the information on a state of use of resources.



Description:


BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mobile communication system, a base station, a radio network controller, and a resource allocation control method used therefor. In particular, the present invention relates to allocation of resources such as codes from a radio network controller to a base station in HSDPA (High Speed Downlink Packet Access).

2. Description of the Prior Art

A mobile communication system such as the W-CDMA (Wideband-Code Division Multiple Access) system uses HSDPA which is a high speed downlink transmission system. In the case in which the HSDPA is provided, it is necessary to set an HS-PDSCH (High Speed-Physical Downlink Shared Channel) and a DPCH (Dedicated Physical Channel) in a downstream.

Here, the DPCH is an individual channel for sending control data. In particular, the ...

Static random access memory (SRAM) cell and method for forming same


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