Sharp Kabushiki Kaisha Corporation

Yozan Corporation

Other

Xiaoling Qin

Guoliang Shou

Changming Zhou

Kunihiko Suzuki

Jie Chen

Mamoru Sawahashi

Makoto Yamamoto

Sunao Takatori

Fumiyuki Adachi

Xuping Zhou

Kazunori Motohashi

Shengmin Lin

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

The present invention provides a matched filter which can refresh an entire while keeping the speed of a calculation comparable to a small sized circuit. The first and second addition circuits of a matched filter of the present invention are classified into a plurality of groups, the first and second auxiliary adders replace functions for the groups of the first and second adders respectively. The outputs of the first and second adders are then inputted to the first and second subtractors, respectively, and the refreshing means appropriately refreshes the groups replaced by the first and second auxiliary adders. Further, the present invention decreases the number of auxiliary sapling and holding circuits to be used, and decides the refreshing intervals by considering the change of the voltage caused by leakage and other permissible errors of output voltage.

Matched filter

An object of the present invention is to provide a matched filter circuit of small size and consuming low electric power. Paying attention that a spreading code is a 1 bit data string, an input signal is sampled and held as an analog signal along the time sequence, classified into '1' and '-1' and the classified signals are added in parallel by capacitive coupling in a matched filter circuit according to the present invention.

Matched filter circuit

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Tokyo, Japan

Xiaoling Qin