摘要:
The present invention has an object to provide a filter circuit largely reducing electric power to consume compared with a conventional one, as well as realizing the first acquisition in enough high speed. In a filter circuit according to the present invention, a matched filter and a sliding correlator are used in parallel, the first acquisition and holding is executed by a matched filter, a correlating operation is executed by a sliding correlator and a voltage is stopped to supply to the matched filter.
摘要:
The present invention has an object to provide a matched filter with further reduced electric power. In a matched filter circuit according to the present invention, the electric power supply is stopped with respect to an unnecessary circuit according to an experience that signal is partially sampled just after the acquisition. Since the spreading code is 1 bit data string, the input signal sampled and held is branched out into the signal groups"1" and "-1" by a multiplexer. The signals in each groups are added in parallel by a capacitive coupling, and the electric power is supplied in the circuit intermittently.
摘要:
The present invention has an object to provide a filter circuit largely reducing electric power to consume compared with a conventional one, as well as realizing the first acquisition in enough high speed. In a filter circuit according to the present invention, a matched filter and a sliding correlator are used in parallel, the first acquisition and holding is executed by a matched filter, a correlating operation is executed by a sliding correlator and a voltage is stopped to supply to the matched filter.
摘要:
The present invention provides a weighted addition circuit for realizing the function of sampling and holding and weighted addition by a smaller circuit than a conventional one. In the weighted addition circuit according to the present invention, a capacitive coupling is connected to a plurality of switches connected only to an input voltage, and a voltage is held and a weight is added in the capacitive coupling.
摘要:
The present invention has an object to provide a matched filter with further reduced electric power. In a matched filter circuit according to the present invention, the electric power supply is stopped with respect to an unnecessary circuit according to an experience that signal is partially sampled just after the acquisition. Since the spreading code is 1 bit data string, the input signal sampled and held is branched out into the signal groups"1" and "-1" by a multiplexer. The signals in each groups are added in parallel by a capacitive coupling, and the electric power is supplied in the circuit intermittently.
摘要:
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.
摘要:
A (direct-sequence code division multiple access) DS-CDMA cellular system includes a plurality of cells each having one base station and a plurality of mobile stations. A signal transmitted form the base station is distinguished by a long code which is different from the others being uniquely allocated to each cell. A long code synchronization timing being detected by a correlation using a common short code. The long codes are searched in each mobile station by a partial correlation in a timing according to the long code synchronization timing. The partial correlation is a correlation between a signal received and a segment of a code defined by a part of the long code, the part being shifted in the long code. Further, the long codes are classified into a plurality of long code groups defined by long code group identification codes. A delay profile of the long code group identification code is detected and is compensated in fading according to said short code. Then, the long code group identification code is combined by rake combining, and is demodulated.
摘要:
A plurality of sets of spreading code sequences are stored in registers. In case of soft hand-over, multi-code and long-delay paths, it is possible that the correlation peaks derived by the different PN sequences overlap. The spreading code sequences then are shifted by the generator registers in order to separate the peaks by one or more chips.