Yozan Corporation

Sharp Kabushiki Kaisha Corporation

Ntt Mobile Communications Network, Inc.

Other

Kokusai Electric Co., Ltd.

Kokusai Electric Corporation

Changming Zhou

Guoliang Shou

Makoto Yamamoto

Sunao Takatori

Xuping Zhou

Mamoru Sawahashi

Fumiyuki Adachi

Kunihiko Suzuki

Kazunori Motohashi

Kenzo Urabe

Takashi Tomatsu

Jie Chen

Xiaoling Qin

Shengmin Lin

Tetsuhiko Miyatani

Ying Chen

Nobuaki Kawahara

Ichiro Matsumoto

Xiaoling Oin

Guolinag Shou

Xiaoxing Zhang

Biqi Long

Masataka Fukui

A matched filter having a set of registers to successively store a digital voltage. The matched filter includes a cumulative shift register, a number of exclusive-or circuits, and an analog adder. The cumulative shift register has a number of stages in which each stage has one bit corresponding to the shift register. The exclusive-or circuits each perform an exclusive-or function on each bit of the digital data and the one bit coefficient while the analog adder sums outputs from the exclusive-or circuits.

Matched filter circuit

An analog calculation circuit in a filter circuit is corrected in the calculation error by estimating the error from a calculation result of known inputs and known multiplier. A multiplier is changed according to the estimated error. The filter circuit has a voltage to current converter at an input side and a current to voltage converter at an output side and a calculation of current is performed therein.

Filter circuit utilizing a plurality of sampling and holding circuits

A plurality of sets of spreading code sequences are stored in registers and selectively supplied to matched filters. The soft-handover, multi-code processing and long-delay paths can be processed by a small circuit.

Signal reception apparatus for DS-CDMA cellular system

Matched filter bank

A signal reception apparatus for DS-CDMA communication system having a complex matched filter for despreading a received signal into I- and Q-components D and D of despread signal. D and D are input to a path selection portion for extracting a phase error in a pilot symbol block of the despread signal. A phase compensation signal is calculated according to the phase error in the portion An information symbol is compensated according to the phase compensation signal. An electrical power is calculated from an average of the phase compensation signal of several slots for selecting paths to be received. The selected paths are combined with phase synchronized by a rake combiner

Signal reception apparatus for DS-CDMA communication system

A matched filter and signal reception apparatus having a low power consumption and small circuitry size. In the matched filter, an analog input signal is converted to digital data by an analog to digital (A/D) converter, digital multiplication, as a correlation calculation, is executed by a plurality of exclusive-OR circuits, and an addition of outputs of the exclusive-OR circuits is performed. In the digital multiplication, the digital data is multiplied by a spreading code of one bit. The outputs from the exclusive-OR circuits are added for each weight of bits, and the addition output results are weighted and summed together.

Matched filter and signal reception apparatus

The present invention offers a method and a circuit for generating codes enabling transmission of long-codes to start on a reverse channel in a shorter waiting time. The method involves corresponding a shift quantity between the beginning of a sequence M or long-codes cycle, and each timing to a combination of a plurality of masking data; determining a combination of masking data for timing to start generation of long-codes in response to a transmission request at a point of time as soon as possible; and shifting of an initial value of a vector according to the masking data.

Method and circuit for codes generation

A receiver for spread spectrum communication system receives a traffic channel and common control channel by a plurality of matched filters at least one of which is selectively available for the traffic or the common control channel. At the initial acquisition, a plurality of matched filters are used for receiving the common control channel. At the hand-over, a plurality of matched filters are used to receive traffic channels of the current base station and the base stations in the adjacent cells.

Spread spectrum communication system

An analog to digital converter comprises a differential input portion that receives an input voltage and a reference voltage and has a first and second output terminals, a positive feedback portion connected to said first and second output terminals, a buffer if CMOSFETs connected at its input to the first output terminal, a second buffer connected at its input to the second output terminal, and a comparison circuit including a first switching portion connected between the first and second output terminals for connecting and disconnecting the first and second output terminals in response to a comparison clock signal. The comparison circuit is connected at its output to the first or second buffer. The input voltage and the reference voltage are compared when said switching portion changes from the connecting condition to the disconnecting condition in response to the comparison clock signal.

Analog to digital converter

A filter circuit comprises a plurality of sampling and holding circuits for sampling and holding analog input signal with a predetermined sampling period, a calculation circuit for multiplying each the analog input signal by a predetermined multiplier, and for summing the multiplication results. The sampling and holding circuits are controlled in an electrical power such that the electrical power is decreased when holding.

Filter circuit

A signal reception apparatus in the spread spectrum communication system requires only a small amount of circuitry and consumes a small amount of electric power. A quadrature detector decomposes received signals into in-phase components and quadrature components, and supplies them to a complex-type matched filter. The complex-type matched filter de-spreads the in-phase components and the quadrature components and sends them to a multi-path selector. The multi-path selector selects, from among the received de-spread signals, multiple paths having high levels of signal electric powers and sends the received signals of the selected paths to multiple phase correction blocks. Analog operation circuits calculate phase errors of the received signals of two successive pilot symbol blocks for each path. An analog operation circuit corrects the phases of the received signals of the information symbol block that has been received between the two successive pilot symbol blocks. A rake combiner synchronously combines the phase-corrected de-spread received signals of each path.

Receiver in a spread spectrum communication system having low power analog multipliers and adders

An output of analog complex matched filter is simplified to be a one dimensional signal such as electrical power. Multi-path detection is performed by the simplified signal. The output of the matched filter is received and processed only when peaks occur in the one dimensional signal.

Receiver apparatus for CDMA communication system

The present invention provides a path-diversity system featuring a small-size phase compensating circuit. This circuit calculates a compensating coefficient according to the signals of a pilot block or a pair of pilot blocks surrounding an information block, and then compensates information signals thereafter by the calculated compensating coefficient.

Path-diversity receiving method and system of spread spectrum communication

The present invention has an object to provide a spread spectrum communication system for heightening the speed of communication. The present invention transfers the first PN code sequence itself as the first component, adds and transfers zero or more instances of the second PN code sequence given a phase difference as the second component, and defines an information for transmitting by the number of the second PN codes corresponding to a cycle of said first PN code sequence.

In one aspect, the present invention provides a low power consumption matched filter. The signal received at an input terminal is input to a shift register having stages equal to the spread code length number after conversion into digital signals in an A/D converter. The outputs of the shift register stages are input to XOR circuits set corresponding to each stage, so that XOR operations are performed between the outputs and corresponding spread code bits d,to d,. The outputs of the XOR circuits are analogously added in an analog adder and output from an output terminal. In another aspect, a filter circuit uses an analog operation circuit to prevent lowered operational accuracy caused by residual charge. Input analog signals successively undergo sampling and holding in sample-and-hold circuits, are multiplied by coefficients stored in a shift register by multiplication circuits, and added in an addition circuit. Sample data transmission error storage is prevented by shifting coefficients in the shift register. Sample-and-hold circuits and multiplication circuits are formed by analog operation circuits, and each include a switch for canceling the residual charge. The sample-and-hold circuits and multiplication circuits normally working are refreshed sequentially by providing circuits for replacing their function. The addition circuit is refreshed in the same way.

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Tokyo, Japan

Changming Zhou