• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Disclosed are methods and apparatus for reducing the adverse effects of adjacent channel interference in stereo receivers for independent sideband type AM stereo signals. In one case such adverse effects are minimized by spatially separating the interference in the reproduced stereo image and making use of the "cocktail party effect". In another case the level of adjacent channel interference in each sideband of the received signal is determined and the selectivity characteristic of the receiver is automatically controlled to discriminate against such interference.
    公开号:SU976864A3
    申请号:SU782573752
    申请日:1978-01-30
    公开日:1982-11-23
    发明作者:Ричард Кан Леонард
    申请人:За витель；
    IPC主号:
    专利说明:

    each of which is cocroitT from bandpass filter 4 and 5, amplifier 6 and 7, demodulator 8 and 9, tunable filter 10 and 11 1xzkah. frequencies, two filters 12 and 13, two detectors 14 and 15, a block 16 of comparison, and a block 17 in the slot and a carrier, paths 18 of low frequency. The receiver operates as follows. Antenna 19 is connected via a high-frequency cascade 1 to an intermediate frequency conversion unit 2 (RF-IF). The intermediate frequency signal from the output of block 2 is fed to UPCH 3. The signal from the output of UPCH 3 goes to two separate channels: the channel of the upper side frequency, the channel of the lower side frequency and block 17 of the carrier split. The channel of the upper side frequency is isolated by a bandpass filter 4, which, in turn, sends a signal to amplifier 6, from which the signal goes to the product demodulator 8. Block 17: & Nor is it used to select a carrier signal and create a clean carrier wave. The lower side frequency is selected by a bandpass filter 5, which in turn sends a signal to the amplifier 7, from which the signal goes to the demodulator 9. The demodulator 9 also receives a signal from the output of the block 17 and does not & a carrier. "The signal from the output of the demodulator about poup on filter 12, from there to detector 14. Similarly, the signal from the output of demodulator 9 goes to filter 13, and from there to detector 15. Filters 12 and 13 and detectors 14 and 15 use to measure the level of interference adjacent to the desired side frequencies. In the modern broadcasting service, carrier-free frequencies in the standard broadcasting range of amplitude modulation in the United States are separated by an interval of 10 kHz. Filters 12 and 13 are used to isolate adjacent channel interference signals. Consequently, filters 13 and 12 should skip V9LNY 10 kHz with a relatively small attenuation. In order to easily measure the carrier level of the adjacent channel, it is necessary that the filters in the high-frequency stage 1, in the IF amplifier 3 and the band-pass filters 4 and 5 of the side frequencies are wide enough to pass the signals, see from the center or from the desired carrier frequency at least by i 10 KDi. The signals at the output of the detector 14 and 15 are fed to the comparison unit 16. Comparison unit 1C determines which of the detectors, 14 or 15, creates a higher level. TaKiiNt way, if the detector 14 produces a signal at the output more, than the detector 15, you can accept that the interference on the upper side frequency is greater than on the lower one. Then, the comparison unit 16, for example, will turn on the lower limit frequency adjustment of the tunable low frequency filter 10. Conversely, if the signal from the output of the detector 15 creates more voltage, it will be assumed that the battery in the channel of the lower side frequency is larger, and the tunable low-frequency filter 11 switches to the lower boundary frequency, and not to the tunable filter 10. Boundary frequencies for tunable filters 10 and 11, it can be made a function of the interference level, or they can be switched by discrete steps. For example, a channel in which the interference level is large can be set to a cutoff frequency, the value of which is equal to one third of the normal total bandwidth that would be used if the channel received a signal relatively free from interference. For a communication service, the cutoff frequency may be 1 kHz. A broadband filter that changes small values of a tag can be stopped with a full pass band, or its bandwidth can be reduced, but by an amount less than that. than on the side frequency where the interference is stronger. The reason that in some cases (it is advisable to lower the frequency response at both side frequencies) is that if the side frequency interferes, this usually indicates that the desired signal is weak. Thus, reducing the bandwidth can help noise control. The signals from the outputs of tunable filters 1O and 11 enter low-frequency paths 18, which consist, for example, of a left transducer for a higher side frequency and of a right transducer for a lower side frequency (not shown). The loudspeaker areas of these devices are common loudspeakers, although in many cases stereo headphones can be used.
    权利要求:
    Claims (1)
    [1]
    1. US patent No. 3537017, cl. 329-122, 197O (prototesh1).
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    同族专利:
    公开号 | 公开日
    SE7801100L|1978-08-01|
    GB1593834A|1981-07-22|
    JPS6121636A|1986-01-30|
    DE2803979C2|1988-09-15|
    BR7800554A|1979-02-13|
    IT1192325B|1988-03-31|
    MX150961A|1984-08-29|
    IL53821D0|1978-04-30|
    NL7801097A|1978-08-02|
    IL53821A|1980-10-26|
    IL59757D0|1980-06-30|
    NL187883C|1992-02-03|
    MX158303A|1989-01-20|
    JPS5396702A|1978-08-24|
    NZ186319A|1983-11-18|
    SE420881B|1981-11-02|
    FR2379192B1|1984-02-24|
    JPS6214974B2|1987-04-04|
    FR2379192A1|1978-08-25|
    DE2803979A1|1978-08-03|
    JPS6341254B2|1988-08-16|
    IT7867175D0|1978-01-30|
    GB1593835A|1981-07-22|
    CA1127717A|1982-07-13|
    AU3258878A|1979-07-26|
    AU513310B2|1980-11-27|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US3218393A|1960-02-11|1965-11-16|Leonard R Kahn|Compatible stereophonic transmission and reception systems, and methods and components characterizing same|
    DE1938838C3|1969-07-28|1979-06-13|Matsushita Electric Industrial Co., Ltd., Kadoma, Osaka |Noise reduction system|
    JPS5225681B1|1970-12-11|1977-07-09|
    US3908090A|1972-05-10|1975-09-23|Leonard R Kahn|Compatible AM stereophonic transmission system|
    US3944749A|1972-05-10|1976-03-16|Kahn Leonard R|Compatible AM stereophonic receivers involving sideband separation at IF frequency|
    US4018994A|1974-07-10|1977-04-19|Kahn Leonard R|Compatible AM stereophonic receivers|
    US3973203A|1972-09-13|1976-08-03|Kahn Leonard R|Carrier isolation system|
    US3947749A|1975-01-31|1976-03-30|Hitachi, Ltd.|Apparatus for generating high voltage for cathode-ray tube|DE3005537A1|1980-02-14|1981-08-20|Wolf, Max, 8103 Oberammergau|Transmission system with line fault rectifying circuit - splits HF into two symmetrical sections supplied to comparator controlling logic|
    US4653095A|1986-02-06|1987-03-24|Kahn Leonard R|AM stereo receivers having platform motion protection|
    JPH0232248U|1988-08-24|1990-02-28|
    US5307515A|1991-08-05|1994-04-26|Ford Motor Company|Adjacent channel controller for radio receiver|
    US5222255A|1991-08-05|1993-06-22|Ford Motor Company|Intermodulation controller for radio receiver|
    DE4241362C2|1992-12-09|1997-06-05|Blaupunkt Werke Gmbh|Radio receiver|
    DE10116358A1|2001-04-02|2002-11-07|Micronas Gmbh|Device and method for the detection and suppression of faults|
    DE10141394A1|2001-08-23|2003-03-13|Siemens Ag|Method for filtering a radio signal to prepare for an EDGE signal calculates signal-to-noise ratios to detect neighboring channel interference during filtering prior to producing a desired signal.|
    DE50202290D1|2001-08-23|2005-03-24|Siemens Ag|ADAPTIVE FILTER PROCESS AND FILTER FOR FILTERING A RADIO SIGNAL IN A MOBILE COMMUNICATION SYSTEM|
    JP2004347474A|2003-05-22|2004-12-09|Sharp Corp|Mobile navigation system|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    US76447677A| true| 1977-01-31|1977-01-31|
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