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US5499267A Expired / Lapsed US ⏱️ 0.0 years remaining

Spread spectrum communication system

Assignee: Yamaha Corp
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Filing: 1993-10-29
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Granted: 1996-03-12
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Expires: 2013-10-29
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Abstract

Abstract A spread spectrum communication system includes a receiving section which receives a signal produced by modulating a carrier of a predetermined frequency with a spread spectrum signal which has been modulated with a spread code of a clock frequency fC and mixes the received signal with a local oscillation signal to provide a spread spectrum signal component wherein a local oscillation frequency fL of said local oscillation signal is set at fL≈fC+fo or fL>fC+fo or fL≈fo-fC or fL<fo-fC where fo represents frequency of said received signal. The received signal may be a signal which has been converted to an intermediate frequency signal after being received by the receiving section. The spread spectrum communication system can prevent a spread spectrum signal from being impaired due to variation in a transmission frequency or oscillation frequency in a receiving section and can thereby accurately demodulate the received signal.

Inventors

  • 👤 Ichirou Ohe
  • 👤 Yutaka Nakamura
  • 👤 Norihiro Suzuki

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 08:12
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/69; H04B1/707

Claims Analysis

Total Claims: 26
Claim 1
Independent Claim 151 words
A spread spectrum communication processing system for a modulated signal produced by modulating a carrier with a spread spectrum signal, the modulated signal having a frequency fo, the spread spectrum signal being modulated with a spread code, the spread code having a clock frequency fc, the spread spectrum communication processing system comprising: an antenna for receiving the modulated signal; and a section for processing the modulated signal, the section connected to said antenna, the section comprising: local oscillation means for supplying a local oscillation signal, the local oscillation signal having a local oscillation frequency fL wherein the local oscillation frequency fL is greater than or equal to approximately fc+fo, mixing means for mixing the modulated signal from said antenna with the local oscillation signal from said local oscillation means, low-pass filter means for extracting a signal containing a component of the spread spectrum signal from an output of said mixing means.
Claim 2
Dependent Claim 151 words
A spread spectrum communication processing system for a modulated signal produced by modulating a carrier with a spread spectrum signal, the modulated signal having a frequency fo, the spread spectrum signal being modulated with a spread code, the spread code having a clock frequency fc, the spread spectrum communication processing system comprising: an antenna for receiving the modulated signal; and a section for processing the modulated signal, the section connected to said antenna, the section comprising: local oscillation means for supplying a local oscillation signal, the local oscillation signal having a local oscillation frequency fL wherein the local oscillation frequency fL is greater than or equal to approximately fc+fo, mixing means for mixing the modulated signal from said antenna with the local oscillation signal from said local oscillation means, low-pass filter means for extracting a signal containing a component of the spread spectrum signal from an output of said mixing means.
Claim 3
Dependent Claim 46 words
A spread spectrum communication processing system as defined in claim 1 further comprising a correlator for correlating the spread spectrum signal with the spread code to demodulate the spread spectrum signal and a demodulator for demodulating an output of the correlator by means of PCM demodulation.
Claim 4
Dependent Claim 143 words
A spread spectrum communication processing system for a modulated signal produced by modulating a carrier with a spread spectrum signal, the modulated signal having a frequency fo, the spread spectrum signal being modulated with a spread code, the spread spectrum code having a clock frequency fc, the spread spectrum communication processing system comprising: an antenna for receiving the modulated signal; and a section connected to said antenna comprising: local oscillation means for supplying a local oscillation signal, the local oscillation signal having a local oscillation frequency fL wherein the local oscillation frequency fL is less than or equal to approximately f-fo, mixing means for mixing the modulated signal from said antenna with the local oscillation signal from said local oscillation means, a low-pass filter for extracting a signal containing a component of the spread spectrum signal from an output of said mixing means.
Claim 5
Dependent Claim 143 words
A spread spectrum communication processing system for a modulated signal produced by modulating a carrier with a spread spectrum signal, the modulated signal having a frequency fo, the spread spectrum signal being modulated with a spread code, the spread spectrum code having a clock frequency fc, the spread spectrum communication processing system comprising: an antenna for receiving the modulated signal; and a section connected to said antenna comprising: local oscillation means for supplying a local oscillation signal, the local oscillation signal having a local oscillation frequency fL wherein the local oscillation frequency fL is less than or equal to approximately f-fo, mixing means for mixing the modulated signal from said antenna with the local oscillation signal from said local oscillation means, a low-pass filter for extracting a signal containing a component of the spread spectrum signal from an output of said mixing means.
Claim 6
Dependent Claim 46 words
A spread spectrum communication processing system as defined in claim 3 further comprising a correlator for correlating the spread spectrum signal with the spread code to demodulate the spread spectrum signal and a demodulator for demodulating an output of the correlator by means of PCM demodulation.
Claim 7
Dependent Claim 157 words
A spread spectrum communication processing system for a modulated signal produced by modulating a carrier with a spread spectrum signal, the spread spectrum signal being modulated with a spread code, the spread spectrum code having a clock frequency fc, the spread spectrum communication processing system comprising: an antenna for receiving the modulated signal; and a receiving section comprising: IF conversion means connected to said antenna for converting the modulated signal into an intermediate frequency signal having a frequency fo, local oscillation means for supplying a local oscillation signal, the local oscillation signal having a local oscillation frequency fL wherein the local oscillation frequency fL is greater than or equal to approximately fc+fo, mixing means for mixing the intermediate frequency signal from said IF conversion means with the local oscillation signal from said local oscillation means, low-pass filter means for extracting a signal containing a component of the spread spectrum signal from an output of said mixing means.
Claim 8
Dependent Claim 157 words
A spread spectrum communication processing system for a modulated signal produced by modulating a carrier with a spread spectrum signal, the spread spectrum signal being modulated with a spread code, the spread spectrum code having a clock frequency fc, the spread spectrum communication processing system comprising: an antenna for receiving the modulated signal; and a receiving section comprising: IF conversion means connected to said antenna for converting the modulated signal into an intermediate frequency signal having a frequency fo, local oscillation means for supplying a local oscillation signal, the local oscillation signal having a local oscillation frequency fL wherein the local oscillation frequency fL is greater than or equal to approximately fc+fo, mixing means for mixing the intermediate frequency signal from said IF conversion means with the local oscillation signal from said local oscillation means, low-pass filter means for extracting a signal containing a component of the spread spectrum signal from an output of said mixing means.
Claim 9
Dependent Claim 72 words
A spread spectrum communication processing system as defined in claim 5 wherein said IF converting means comprises IF local oscillation means for supplying an IF local oscillation signal which has a different frequency from that of said local oscillation means and IF mixing means for mixing the IF local oscillation signal from said IF local oscillation means with the modulated signal from said antenna so as to provide the intermediate frequency signal.
Claim 10
Dependent Claim 46 words
A spread spectrum communication processing system as defined in claim 5 further comprising a correlator for correlating the spread spectrum signal with the spread code to demodulate the spread spectrum signal and a demodulator for demodulating an output of the correlator by means of PCM demodulation.
Claim 11
Dependent Claim 158 words
A spread spectrum communication processing system for a modulated signal produced by modulating a carrier with a spread spectrum signal, the spread spectrum signal being modulated with a spread spectrum code, the spread spectrum code having a clock frequency fc, the spread spectrum communication processing system comprising: an antenna for receiving the modulated signal; and a receiving section comprising: IF conversion means connected to said antenna for converting the modulated signal into an intermediate frequency signal having a frequency fo, local oscillation means for supplying a local oscillation signal, the local oscillation signal having a local oscillation frequency fL wherein the local oscillation frequency fL is less than or equal to approximately fc-fo, mixing means for mixing the intermediate frequency signal from said IF conversion means with the local oscillation signal from said local oscillation means, low-pass filter means for extracting a signal containing a component of the spread spectrum signal from an output of said mixing means.
Claim 12
Dependent Claim 158 words
A spread spectrum communication processing system for a modulated signal produced by modulating a carrier with a spread spectrum signal, the spread spectrum signal being modulated with a spread spectrum code, the spread spectrum code having a clock frequency fc, the spread spectrum communication processing system comprising: an antenna for receiving the modulated signal; and a receiving section comprising: IF conversion means connected to said antenna for converting the modulated signal into an intermediate frequency signal having a frequency fo, local oscillation means for supplying a local oscillation signal, the local oscillation signal having a local oscillation frequency fL wherein the local oscillation frequency fL is less than or equal to approximately fc-fo, mixing means for mixing the intermediate frequency signal from said IF conversion means with the local oscillation signal from said local oscillation means, low-pass filter means for extracting a signal containing a component of the spread spectrum signal from an output of said mixing means.
Claim 13
Dependent Claim 72 words
A spread spectrum communication processing system as defined in claim 8 wherein said IF converting means comprises IF local oscillation means for supplying an IF local oscillation signal which has a different frequency from that of said local oscillation means and IF mixing means for mixing the IF local oscillation signal from said IF local oscillation means with the modulated signal from said antenna so as to provide the intermediate frequency signal.
Claim 14
Dependent Claim 46 words
A spread spectrum communication processing system as defined in claim 8 further comprising a correlator for correlating the spread spectrum signal with the spread code to demodulate the spread spectrum signal and a demodulator for demodulating an output of the correlator by means of PCM demodulation.
Claim 15
Dependent Claim 161 words
A spread spectrum communication processing system for a modulated signal produced by modulating a carrier with a spread spectrum signal, the modulated signal having a center frequency fo, the spread spectrum signal being modulated with a spread code, the spread code having a clock frequency fc, the spread spectrum communication processing system comprising: modulation signal receiving means for receiving the modulated signal, and a processing section comprising: local oscillation means for supplying a local oscillation signal, the local oscillation signal having a local oscillation frequency fL wherein the local oscillation frequency fL is substantially greater than or equal to about an absolute value of the frequency difference between the clock frequency fc and the frequency fo, mixing means for mixing the modulated signal from said modulation signal receiving means with the local oscillation signal from said local oscillation means, low-pass filter means for extracting a signal containing a component of the spread spectrum signal from an output of said mixing means.
Claim 16
Dependent Claim 161 words
A spread spectrum communication processing system for a modulated signal produced by modulating a carrier with a spread spectrum signal, the modulated signal having a center frequency fo, the spread spectrum signal being modulated with a spread code, the spread code having a clock frequency fc, the spread spectrum communication processing system comprising: modulation signal receiving means for receiving the modulated signal, and a processing section comprising: local oscillation means for supplying a local oscillation signal, the local oscillation signal having a local oscillation frequency fL wherein the local oscillation frequency fL is substantially greater than or equal to about an absolute value of the frequency difference between the clock frequency fc and the frequency fo, mixing means for mixing the modulated signal from said modulation signal receiving means with the local oscillation signal from said local oscillation means, low-pass filter means for extracting a signal containing a component of the spread spectrum signal from an output of said mixing means.
Claim 17
Independent Claim 94 words
A method for processing a spread spectrum signal including a data signal generated through the use of a spread spectrum transmission technique using a pseudo random code having a clock frequency of fc, the spread spectrum signal centered around a carrier at a frequency of fo, the processing method comprising: providing a local signal having a frequency fL, the magnitude of the difference in the frequency of fL and fo being approximately greater than or equal to fc; and mixing the generated local signal with the spread spectrum signal to generate a mixed signal.
Claim 18
Independent Claim 94 words
A method for processing a spread spectrum signal including a data signal generated through the use of a spread spectrum transmission technique using a pseudo random code having a clock frequency of fc, the spread spectrum signal centered around a carrier at a frequency of fo, the processing method comprising: providing a local signal having a frequency fL, the magnitude of the difference in the frequency of fL and fo being approximately greater than or equal to fc; and mixing the generated local signal with the spread spectrum signal to generate a mixed signal.
Claim 19
Dependent Claim 39 words
The method of claim 12, the method further including low pass filtering the mixed signal to extract a data signal modulated with a pseudo random code; and demodulating the data signal from the output of the low pass filter.
Claim 20
Dependent Claim 31 words
The method of claim 12, wherein the spread spectrum transmission technique involves transmitting at a frequency f'o, the method further comprising heterodyning the transmitted signal to an intermediate frequency of fo.
Claim 21
Independent Claim 128 words
An apparatus for processing a spread spectrum signal including a data signal generated through the use of a spread spectrum transmission technique using a pseudo random code having a clock frequency of fc, the spread spectrum signal centered around a carrier at a frequency of fo, the processing method comprising: a signal generator generating a signal having a frequency fL, the magnitude of the difference in the frequency of fL and fo being approximately greater than or equal to fc; and a frequency shifting circuit responsive to the generated local signal and the spread spectrum signal to generate an output spread spectrum signal in a frequency band centered at a frequency greater than or equal to about the magnitude of the difference in the frequencies fL and fo.
Claim 22
Independent Claim 128 words
An apparatus for processing a spread spectrum signal including a data signal generated through the use of a spread spectrum transmission technique using a pseudo random code having a clock frequency of fc, the spread spectrum signal centered around a carrier at a frequency of fo, the processing method comprising: a signal generator generating a signal having a frequency fL, the magnitude of the difference in the frequency of fL and fo being approximately greater than or equal to fc; and a frequency shifting circuit responsive to the generated local signal and the spread spectrum signal to generate an output spread spectrum signal in a frequency band centered at a frequency greater than or equal to about the magnitude of the difference in the frequencies fL and fo.
Claim 23
Dependent Claim 184 words
A spread spectrum communication receiving system for a modulated signal produced by modulating a carrier with a spread spectrum signal, the modulated signal having a frequency fo, the spread spectrum signal being modulated with a spread code, the spread code having a clock frequency fc, the spread spectrum communication receiving system comprising: an antenna for receiving the modulated signal; and a receiving section for the modulated signal connected to said antenna comprising: local oscillation means for supplying a local oscillation signal, the local oscillation signal having a local oscillation frequency fL wherein the local oscillation frequency fL is substantially greater than or equal to approximately an absolute value of the frequency difference between the clock frequency fc and the frequency fo, mixing means for mixing the modulated signal from said antenna with the local oscillation signal from said local oscillation means, low-pass filter means for extracting a signal containing a component of the spread spectrum signal from an output of said mixing means, a means for correlating coupled to an output of the filter, and a means for demodulating an output of the correlator.
Claim 24
Dependent Claim 184 words
A spread spectrum communication receiving system for a modulated signal produced by modulating a carrier with a spread spectrum signal, the modulated signal having a frequency fo, the spread spectrum signal being modulated with a spread code, the spread code having a clock frequency fc, the spread spectrum communication receiving system comprising: an antenna for receiving the modulated signal; and a receiving section for the modulated signal connected to said antenna comprising: local oscillation means for supplying a local oscillation signal, the local oscillation signal having a local oscillation frequency fL wherein the local oscillation frequency fL is substantially greater than or equal to approximately an absolute value of the frequency difference between the clock frequency fc and the frequency fo, mixing means for mixing the modulated signal from said antenna with the local oscillation signal from said local oscillation means, low-pass filter means for extracting a signal containing a component of the spread spectrum signal from an output of said mixing means, a means for correlating coupled to an output of the filter, and a means for demodulating an output of the correlator.
Claim 25
Independent Claim 117 words
A method for processing a spread spectrum signal including a data signal generated through the use of a spread spectrum transmission technique using a pseudo random code having a clock frequency of fc, the spread spectrum signal centered around a carrier at a frequency of fo, the processing method comprising: providing a local signal having a frequency fL, the magnitude of the difference in the frequency of fL and fo being approximately greater than or equal to fc; and mixing the generated local signal with the spread spectrum signal to generate a mixed signal, filtering the mixed signal to provide a filter signal, correlating the filtered signal to provide a correlated signal, and demodulating the correlated signal.
Claim 26
Independent Claim 117 words
A method for processing a spread spectrum signal including a data signal generated through the use of a spread spectrum transmission technique using a pseudo random code having a clock frequency of fc, the spread spectrum signal centered around a carrier at a frequency of fo, the processing method comprising: providing a local signal having a frequency fL, the magnitude of the difference in the frequency of fL and fo being approximately greater than or equal to fc; and mixing the generated local signal with the spread spectrum signal to generate a mixed signal, filtering the mixed signal to provide a filter signal, correlating the filtered signal to provide a correlated signal, and demodulating the correlated signal.

References Cited (Backward Citations)

US3475558A Cited
US4962508A Cited
US4736390A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1999-03-12 1999-09-11 2000-03-12 $2000.00 Window Closed / Lapsed
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