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US 7,120,397 B2Granted
All-frequency-band SSB radio communication system and radio apparatus
AssigneeYoji Makishima
InventorsMasaki Tatemori, Yoji Makishima
Life of this patent
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AssigneeYoji Makishima
InventorsMasaki Tatemori, Yoji Makishima
Estimating the term…
An SSB radio communication system and radio apparatus applicable to ultra high frequencies such as a VHF band and UHF band. In the transmitting side, a carrier wave is amplitude modulated by modulation input signals which comprise a constant amplitude, sine wave shaped reference pulse having a predetermined width and period and a sine wave shaped modulation pulse signal having an amplitude representing two- or multi-value digital values having the same width as the reference pulse signal and which are formed based on the amplitude of the reference pulse signal, and the modulated pulse signals are transmitted on a single side band, while in its receiving side the gain of received signals is automatically adjusted based on the reference pulse signal that is the value of the peak of the received signals. Further, in the transmitting side, the period or frequency of the reference pulse signal is also formed in synchronism with the carrier wave frequency, and in the receiving side, a local carrier wave frequency to be given to a demodulator is determined based on the period of frequency of the reference pulse signal.
An SSB radio communication system comprising:
A radio apparatus comprising:
A radio apparatus comprising:
A radio apparatus for receiving single side band communication signals modulated by modulation inputs, wherein said modulation inputs comprise a constant amplitude, sine wave shaped reference pulse signal, formed based on a carrier frequency, having a predetermined width and a predetermined period, and sine wave shaped modulation pulse signals having the same width as the reference pulse signal and amplitudes representing two- or multi-value digital values based on the amplitude of the reference pulse signal, the apparatus comprising,
Dependencies are inferred from the claim text.
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This invention relates to an SSB radio communication system using a single side band (SSB) and radio apparatus therefor, particularly a radio system or apparatus which has advanced efficiency in using frequencies, and which is usable in ultra high frequency bands such as a VHF band, UHF band, and the like.
An SSB radio communication system is widely used, wherein wireless communications are carried out by using amplitude modulation signals.
In this SSB radio communication system, a carrier wave and one of upper and lower side band waves that do not contribute directly to the transmission of information are suppressed, and only either one of the upper and lower side band waves is transmitted. This system not only saves electric power but also can use a number of communication channels by using only a half the frequency band.
FIG. 1 is a block diagram showing receiving circuits of a radio apparatus using the conventional SSB radio communication system.
FIG. 2 is a schematic showing the whole structure of the transmitting side of a radio apparatus of the SSB radio communication system of this invention.
FIG. 3 is a diagram showing the waveforms of signals in each part of FIG. 2.
FIG. 2 is a schematic showing the whole structure of the transmitting side of an embodiment of the radio apparatus of the SSB radio communication system of this invention. FIG. 3 is a diagram showing the waveforms of signals in each part of FIG. 2.
In this embodiment, wherein multi-values (four values) of digital signals are transmitted, a clock signal frequency of 1.8 kHz used as only a modulation frequency synchronized with a carrier wave is selected, signals are carried on each value of its amplitude per its cycle, a reference signal with the largest constant amplitude and constant interval is placed in one of the signals, and one data signal is inserted therebetween (a plurality of data signals may also be inserted).
In FIG. 2, a sine wave generator 31 receives from a transmitting circuit 35 a reference signal (ref) based on its carrier wave frequency, and both a clock signal (a) of 1.8 kHz, having a constant amplitude and a duty ratio of 50%, and a sine wave signal (c) of 1.8 kHz are outputted to be fed to a resistance attenuator part 32. The resistance attenuator part 32 consists of five resistance attenuators 1–5 to correspond to both the reference signal and the four values of data signals.
Using a first intermediate frequency higher that the highest of any band received: using a wideband front end
Homodyne or synchrodyne circuits: for demodulation of signals wherein one sideband or the carrier has been wholly or partially suppressed
Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised…
For homodyne or synchrodyne receivers: for single sideband receivers
Term ended 12 Dec 2023 (estimated)