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1.发明授权
公开(公告)号：US5298897A
公开(公告)日：1994-03-29
申请号：US822595
申请日：1992-01-17
CPC分类号： G11B20/1419
摘要： A two-frequency data signal, also known as a biphase or F/2F signal, is accurately decoded by sampling the signal and digitizing the samples to provide a series of digital values representing the signal. An intelligent digital filter manipulates the digital values to decode the signal, by detecting the peaks in the sampled signal and decoding the signal by analyzing the location and amplitudes of the peaks. Only peaks which are outside a guard band may be detected. If the signal cannot be properly decoded with a wide guard band, the guard band may be repeatedly narrowed, until a minimum guard band is reached. Bits are identified by comparing the displacements between peaks to a bit cell width. An even number of displacements indicates a `0` bit, and an odd number of displacements indicates a `1` bit. After decoding, the bits are converted into bytes. Parity and longitudinal redundancy code checks are used to correct bad bits. During decoding, many indications of a degraded signal may be obtained. If a degraded signal is indicated, the host computer is notified, even though the signal was properly read. Card replacement can then be initiated at the first signs of signal degradation, before the data signal becomes unreadable.
摘要翻译： 也称为双相或F / 2F信号的双频数据信号通过对信号进行采样并对样本进行数字化来精确地解码，以提供表示信号的一系列数字值。 智能数字滤波器通过检测采样信号中的峰值并通过分析峰值的位置和振幅对信号进行解码，来操纵数字值对信号进行解码。 只能检测到保护带外的峰值。 如果信号不能用宽的保护频带正确解码，则保护频段可能会被重复变窄，直到达到最小保护频带。 通过将峰之间的位移与位单元宽度进行比较来识别位。 偶数位移表示“0”位，奇数位移表示“1”位。 解码之后，这些位被转换成字节。 奇偶校验和纵向冗余码检查用于校正坏位。 在解码期间，可以获得许多恶化信号的指示。 如果指示了降级信号，即使信号被正确读取，也会通知主计算机。 然后，在数据信号变得不可读之前，可以在信号劣化的第一个迹象处启动卡替换。
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2.发明授权
公开(公告)号：US5168275A
公开(公告)日：1992-12-01
申请号：US477320
申请日：1990-02-07
CPC分类号： G11B20/1419
摘要： A two-frequency data signal, also known as a biphase or F/2F signal, is accurately decoded by sampling the signal and digitizing the samples to provide a series of digital values representing the signal. An intelligent digital filter manipulates the digital values to decode the signal, by detecting the peaks in the sampled signal and decoding the signal by analyzing the location and amplitudes of the peaks. Only peaks which are outside a guard band may be detected. If the signal cannot be properly decoded with a wide guard band, the guard band may be repeatedly narrowed, until a minimum guard band is reached.Bits are identified by comparing the displacements between peaks to a bit cell width. An even number of displacements indicates a `0` bit, and an odd number of displacements indicates a `1` bit. Once a bit is decoded, the bit cell width is incremented by a predetermined amount if the bit cell width is wider than the current bit cell width, and is decremented by a predetermined amount if the decoded bit cell width is narrower than the current bit cell width. If no peaks are found within a maximum allowable bit cell width, this area is delimited as bad. An attempt is made to decode the bits in the bad area by analyzing all peaks without regard to a guard band. After decoding, the bits are converted into bytes. Parity and longitudinal redundancy code checks are used to correct bad bits.
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公开(公告)号：US5379037A
公开(公告)日：1995-01-03
申请号：US128986
申请日：1993-09-29
CPC分类号： G11B20/1419
摘要： A two-frequency data signal, also known as a biphase or F/2 F signal, is accurately decoded by sampling the signal and digitizing the samples to provide a series of digital values representing the signal. An intelligent digital filter manipulates the digital values to decode the signal, by detecting the peaks in the sampled signal and decoding the signal by analyzing the location and amplitudes of the peaks. Only peaks which are outside a guard band may be detected. If the signal cannot be properly decoded with a wide guard band, the guard band may be repeatedly narrowed, until a minimum guard band is reached.Bits are identified by comparing the displacements between peaks to a bit cell width. An even number of displacements indicates a `0` bit, and an odd number of displacements indicates a `1` bit. After decoding, the bits are converted into bytes. Parity and longitudinal redundancy code checks are used to correct bad bits.During decoding, many indications of a degraded signal may be obtained. If a degraded signal is indicated, the host computer is notified, even though the signal was properly read. Card replacement can then be initiated at the first signs of signal degradation, before the data signal becomes unreadable.
摘要翻译： 也被称为双相或F / 2F信号的双频数据信号通过对信号进行采样并将样本数字化以提供表示该信号的一系列数字值而被精确解码。 智能数字滤波器通过检测采样信号中的峰值并通过分析峰值的位置和振幅对信号进行解码，来操纵数字值对信号进行解码。 只能检测到保护带外的峰值。 如果信号不能用宽的保护频带正确解码，则保护频段可能会被重复变窄，直到达到最小保护频带。 通过将峰之间的位移与位单元宽度进行比较来识别位。 偶数位移表示“0”位，奇数位移表示“1”位。 解码之后，这些位被转换成字节。 奇偶校验和纵向冗余码检查用于校正坏位。 在解码期间，可以获得许多恶化信号的指示。 如果指示了降级信号，即使信号被正确读取，也会通知主计算机。 然后，在数据信号变得不可读之前，可以在信号劣化的第一个迹象处启动卡替换。
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