The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 25, 1996
Filed:
Jul. 19, 1994
Kimio Watanabe, Kawasaki, JP;
Fujitsu Limited, Kanagawa, JP;
Abstract
A PN code demodulator reduced in hardware scale and a code-division multiplex communication apparatus using the PN code demodulator are provided wherein the quantity of external noise is detected during communications and the number of multiplexed channels can be immediately changed in accordance with the quantity of external noise. In the PN code demodulator, an exclusive-OR unit derives an exclusive-OR of a PN code and a baseband signal modulated by the PN code. A counting unit counts the number of anticoincidence bits at which the baseband signal does not coincide with the PN code, based on the output of the exclusive-OR unit over a predetermined code length. A determining unit and a restoring unit restore a data signal in accordance with whether the number of anticoincidence bits counted by the counting unit has reached the value of the (predetermined code length+1)/2. A correlation value output unit obtains a correlation value based on the count value of the counting unit. In the code-division multiplex communication apparatus, the number of multiplexed channels is controlled in accordance with the correlation value.