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US 2006/0233220 A1Published application
Wireless telephone with spectral spread in sampled voice
AssigneeIntelibras S/A
InventorJoao Coata
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AssigneeIntelibras S/A
InventorJoao Coata
Estimating the term…
A cordless telephone handset and a cordless telephone base station both comprise a transmitter unit and a receiver unit is presented whereby the communication between said handset and said base station is established over a radio link utilizing an analogue based spread spectrum communication technique whereby at the transmitter unit the analogue voice signal is sampled by means of a sample and hold unit, frequency modulated by means of a voltage controlled oscillator (VCO) and the spectrum of said modulated carrier signal is spread by a mixer through a PN sequence, which is produced by a PN sequence generator, thereby producing a spread spectrum frequency modulated carrier signal for transmission over said radio link to the receiver unit whereby at the receiver said spread and frequency modulated carrier signal is received (1) and de-spread by means of a mixer through a PN sequence which is regenerated by means of a delay locked code tracking loop (DLL) and demodulated by means of a frequency demodulator whereby at the receiver unit the analogue voice signal (5) is finally generated by means of a hold circuit and a bans pass filter.
“WIRELESS TELEPHONE EQUIPMENT WITH SPECTRAL SPREAD IN SAMPLED VOICE”, characterized for being composed of base and portable (handset), being that both use transmitters and receivers with the “Spectral Spread in Sampled Voice” concept whose diagrams in sections and wave forms are shown in FIGS. (3A), (3B), (4A) and (4B), and that present diagrams of the portable set and base as shown in FIGS. (1) and (2) respectively, and because they use transmitter and receiver under the “Spectral Spread in Sampled voice” concept, allow reduction in battery consumption and discard the need to operate in distinct bands for transmission and reception in relation to wireless telephone using spectral spread in analog voice, and that for not digitizing voice presents the advantage of not needing analog/digital converters, level quantifier circuits, generating considerable reduction in costs and for allowing small time delays in transmission and reception discards use of echo canceling circuits, as used by digital phones which spread or not the frequency spectrum, allowing for raw material costs reduction.
“WIRELESS TELEPHONE EQUIPMENT WITH SPECTRAL SPREAD IN SAMPLED VOICE” according to claim in 1, characterized by a transmitter which allows its application in any transmission equipment of analog signals by radio, and that consists of sampling the signal to be transmitted through Sample-and-Hold (S/H), limiting the duration of each sample to the transmission pulse duration and making them modulate in one carrier frequency during the transmission pulse, which is simultaneously modulated in phase by PN sequence that promotes spectral spread of transmitted signal in direct sequence, which presents delay in hundreds of micro-secs, quite shorter than that caused by transmitters that digitize voice, and therefore allowing the manufacturing of wireless phones and PABX without echo canceling circuits and for their transmitting in short interval allow turning reception off for the user to receive signals in the same frequency, eliminating the need for duplexers and two distinct bands for transmission/reception in a given equipment, and which shall operate in sync with the receiver under the concept of “Spectral Spread in Sampled Voice”, and that in conjunction with the “Spectral Spread in Sampled Voice” enables greater communication range under the laws in force regulating and allowing greater power for equipment using spectral spread transmission.
Dependencies are inferred from the claim text.