Kokusai Electric Co., Ltd.

Yozan Corporation

Hitachi, Ltd.

Kokusai Electric Corporation

Ericsson Gmbh

Hitachi-kokusai Electric Inc.

Kenzo Urabe

Guoliang Shou

Changming Zhou

Tetsuhiko Miyatani

Makoto Yamamoto

Sunao Takatori

Hideto Yamaguchi

Kazuo Tanaka

Kazuhiro Suzuki

Shunji Abe

Xuping Zhou

Hideya Suzuki

Ichiro Imaizumi

Tsuneo Furuya

Yoshinobu Yamamoto

Hitoshi Kato

Yi-Pin Eric Wang

Gregory Edward Bottomley

Hiroshi Kuwahara

Naoki Hongo

Yoshihiko Akaiwa

Arata Nakagoshi

Yohichi Ogawa

Seishi Sasaki

Masatoshi Takada

Nobuaki Kawahara

Masayasu Miyake

Yasuhiro Murayama

Masaki Tanaka

Hiroko Ono

Toshikazu Sasa

Zhou Changming

Yoshikuni Itoh

Syunji Tochihara

Atsushi Hoshi

Giho Makino

Seigo Miyoshi

Methods of recovering information encoded in a spread spectrum signal transmitted according to a spreading sequence in a communications medium are provided in which a spread spectrum signal is received from the communications medium and correlated with a spreading sequence to produce a plurality of time-offset correlations. Some of these time-offset correlations may be designed to cancel out known interfering signals. A subset of the plurality of time-offsets may then be selected, and corresponding traffic correlations may then be combined using a weighted combination to estimate information encoded in the transmitted spread spectrum signal. Receivers for implementing these methods are also provided.

Apparatus and methods for finger delay selection in RAKE receivers

A temperature control simulation method and apparatus for forming a temperature system simulation model on a computer, provide substantially the same response or simulation characteristics as a temperature change in an actual furnace, whereby a temperature control algorithm can be developed and the method or manner of manipulating the temperature control can be learned without using an actual furnace. A transfer function is determined which represents a relationship between a heater input and a temperature output. A temperature control simulation for a heating furnace is executed using the transfer function of a heating furnace as a transfer function that a temperature system simulation device uses.

Temperature control simulation method and apparatus

A mobile station (mobile communication unit) receives system software from a base station via an antenna and a transmitter/receiver, and stores the received system software in a memory. A digital signal processor in the mobile station then performs communication processing according to the system software stored in the memory. By transmitting various system software from the base station, the single mobile station can easily be adapted to different communication principles. The base station also receives system software from a center via a public exchange network, and stores the received system software in a memory. A digital signal processor in the base station then performs communication processing according to the system software stored in the memory.

Mobile communication unit and mobile communication system

A despreading circuit which can reduce a circuit scale and power consumption is described. The circuit includes an A/D converter which converts a CDMA modulated analog signal to a digital signal of N bits, and a searcher which defects a synchronization phase from high-order small bits of the N bits and outputs synchronozation phase information to a control circuit. The control circuit transmits a signal for allowing despreading to be performed to a sliding correlator based on the phase information. The sliding correlator despreads the N bit digital signal outputted by the A/D converter and outputs the resulting correlation output as a despreading signal.

Despreading circuit

A semiconductor producing apparatus is capable of quickly and accurately changing a controlled variable to a target value to thereby make the controlled variable quickly follow the target value. Moreover, the controlled variable and target value can be adjusted automatically, thus improving the productivity of a process. The semiconductor producing apparatus includes a PID adjustment section to which a target value and a detected control value are inputted through an adder, a pattern generation section having an approximate function for calculating a pattern output and making it possible to change the pattern output in accordance wit parameter values of the approximate function, and a switcher for switching between an output including at least an output of the pattern generation section and an output of the PID adjustment section to thereby generate an output.

Semiconductor producing apparatus and temperature control method therefor

The present invention intends to provide a receiver which receives a signal by switching a plurality of communication systems, wherein a circuit scale is reduced to intend to the miniaturization of a device. The receiver converts a received signal to a base band signal by a local oscillation frequency based on the selected communication system by a mixer, limits a band by an LPF through which signals of all communication systems can pass, performs a band limitation based on the communication system by weighting with a tap coefficient based on the selected communication system to synthesis by a transversal filter, and demodulates a signal by a demodulation system based on the selected communication system by a demodulating unit.

Receiver

A despreading circuit which can reduce a circuit scale and power consumption is described. The circuit includes an A/D converter which converts a CDMA modulated analog signal to a digital signal of N bits, and a searcher which detects a synchronization phase from high-order small bits of the N bits and outputs synchronization phase information to a control circuit. The control circuit transmits a signal for allowing despreading to be performed to a sliding correlator based on the phase information. The sliding correlator despreads the N bit digital signal outputted by the A/D converter and outputs the resulting correlation output as a despreading signal.

A correlating filter includes a delay circuit which outputs a plurality of tap output signals TP1 to TPn having different delays. The correlating filter further includes a weighted adder circuit which weights the tap output signals, respectively, and adds the weighted tap output signals so as to derive a correlated output signal. A timing control circuit produces a control signal based on the correlated output signal from the weighted adder circuit. The control signal is high in level when the correlated output signal has a correlation peak. A power feed to the weighted adder circuit is achieved via a switching element. The switching element is only turned on when the control signal is high in level so as to enable the power feed to the weighted adder circuit. Thus, reduction in power consumption is achieved and the filter can be used in a portable radio device.

Correlating filter and CDMA receiver

A signal characterizer for performing functional transformations such as Fast Fourier Transforms (FFTs), which converts an input serial analog signal into a plurality of parallel discrete signals using an analog-type serial-to-parallel converter. The discrete signals are then supplied to the input terminals of butterfly operation circuits to process the parallel discrete signals into a plurality of transformed signals. A switch supplies the transformed signals to a serial signal output terminal. The switch is controlled by a controller so that the input signal sequence is converted to a serial signal sequence according to a predetermined order.

Analog signal characterizer for functional transformation

A multi-user demodulator eliminates synchronization problems without interference cancellation. A threshold process is applied to a despread signal to extract each user's signal. The extracted signals are respread, and those respread signals other than a specifier user's signal are subtracted from the received signal to ideally extract the specific user's signal.

Multi-user demodulator for CDMA spectrum spreading communication

A fast spread spectrum communication system is provided, having fewer circuits and requiring fewer PN codes to be assigned to a user. A series of digital data to be transmitted, is divided into 4-bit frames. The 4-bit data of each frame is divided into the first through fourth elements in a predetermined order. The first complex number is constructed by the first and second elements, and the second complex number is determined according to the value of the third and fourth elements. The spectrum of the data to be transmitted is spread by multiplying these complex numbers. Four matched filters despread a received signal by different combinations of PN codes stored in a receiver. The first through fourth elements are recovered according to the outputs of the matched filters.

Spread spectrum communications system for high-speed communications

The present invention solves the conventional problems and has an object to provide a matched filter system of high process in speed, a small size and low electric power consumption. The matched filter circuits of each matched filter set is allocated different n combinations of M/n digits selected from the M length PN code sequence picking one out of every n digits, cyclically performs sampling every 1 chip time duration the input signals to be inputted to each set constructed by matched filter circuits by n sets each of which including n matched filter circuits, and calculates the sum of outputs of all matched filter circuits.

Matched filter system

The demodulator has a plurality of matched filters in parallel. Each matched filter has a different binary PN code, a plurality of sample holders, a plurality of multipliers, an adder, and a controller. The sample holders has a common input, a switch, a first capacitor, a first inverse amplifier with an output and an input connected to the common input through the switch and the capacitor, and a first feedback capacitor for feeding the output of the first inverse amplifier back to the input. Each multiplier has a first and second sub-multiplexers, one of sub-multiplexer selecting corresponding sample holder output and another sub-multiplexer selecting a reference voltage.

Demodulator for CDMA spread spectrum communication using multiple pn

There is disclosed an acceptable error detector for error correcting block codes, in which of received syndrome vectors S for the received word vectors Y available from the syndrome generator, the m.sub.e -bit received subsyndromes S(m.sub.e) formed by the same components as those of the m.sub.e -bit representative subsyndromes &lt;S(m.sub.e)&gt; uniquely corresponding to the vectors of all the acceptable error pattern with error bits equal to or less than the acceptable number e is applied as addresses into the redundant subsyndrome table memory. Since the stored data specified by the input address are (m-m.sub.e)-bit redundant subsyndromes &lt;S(m-m.sub.e)&gt; which are supposed to appear in the remaining portion of S(=&lt;S&gt;) when the number of error bits is equal to or less than e, the remaining (m-m.sub.e)-bit received subsyndromes S(m-m.sub.e) derived from the received word vector Y in the syndrome generator and the (m-m.sub.e)-bit redundant subsyndrome &lt;S(m-m.sub.e)&gt; obtained from the redundant subsyndrome table memory are compared with each other by a coincidence detector to detect coincidence or noncoincidence therebetween. By this configuration, it is possible to detect whether the number of error bits in received word is acceptable.

Error detector for error detecting codes

An intermittenceless switching system includes two speech path memories having sufficient capacity to store a single frame of data having a plurality of time slots. The incoming data is stored in one memory, while the outgoing data is read from the other memory. A control circuit continuously alternates the read/write functions between the two memories. A control memory is used to store switch control information. The system includes a buffer memory that is present between a data processor and the control memory to prevent switch operation during data transmission. The system also includes a monitoring circuit for detecting an indication bit signifying the presence or absence of data in the time slot.

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Tokyo, Japan

Kenzo Urabe