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1.发明申请
公开(公告)号：WO0158173A2
公开(公告)日：2001-08-09
申请号：PCT/US0103340
申请日：2001-02-01
Applicant: MOTOROLA INC
Inventor： PILOZZI JOHN , KIM DAE-YOUNG , MEHRABANZAD SEPEHR , LIU JACK , AHMED S ARIF , PARIZHSKY VLADIMIR
CPC classification number: H04L25/4927
Abstract: A system and method for adjusting the phase of the analog signal produced by an analog modem (26) connected to a digital modem (20) over a telephone network (22). The digital portion of the telephone network is locked to the network clock, and the modems (20 and 26) have no control over the sampling timing or rate as the analog signal is sampled and quantized by a codec (23). If the analog signal is shifted in phase relative to the network clock, the codec (23) may be sampling at unresolvable points on the analog signal, thereby causing errors and a decrease in the usable bandwidth for transmitting data. The analog modem (26) symbol frequency is locked (101) to the clock of the digital network (22) using loop-back timing. A phase estimate (103) is computed using the quantized samples of a known reference signal. Next, a phase offset (105) is calculated by comparing the phase estimate to an optimum phase value. Then the digital modem (20) sends the calculated phase offset information (107) to the analog modem (26). The analog modem (26) then delays its transmitted signal by the phase offset (109). After the phase of the analog modem's transmitter is adjusted, the analog signal reaches the codec (23) at the phase desired by the digital modem (20).
Abstract translation: 一种用于调节通过电话网络（22）连接到数字调制解调器（20）的模拟调制解调器（26）产生的模拟信号的相位的系统和方法。 电话网络的数字部分被锁定到网络时钟，并且当模拟信号被编解码器（23）采样和量化时，调制解调器（20和26）不能控制采样定时或速率。 如果模拟信号相对于网络时钟相位移位，则编解码器（23）可以在模拟信号上的不可解析点进行采样，从而导致发送数据的可用带宽的错误和降低。 使用环回定时将模拟调制解调器（26）符号频率锁定（101）到数字网络（22）的时钟。 使用已知参考信号的量化采样来计算相位估计（103）。 接下来，通过将相位估计与最佳相位值进行比较来计算相位偏移（105）。 然后数字调制解调器（20）将计算的相位偏移信息（107）发送到模拟调制解调器（26）。 模拟调制解调器（26）然后将其发送的信号延迟相位偏移（109）。 在模拟调制解调器的发射机的相位被调整之后，模拟信号以数字调制解调器（20）所期望的相位达到编解码器（23）。
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公开(公告)号：BR9814538A
公开(公告)日：2001-10-02
申请号：BR9814538
申请日：1998-11-13
Applicant: MOTOROLA INC
Inventor： EYUBOGLU M VEDAT , KIM DAE-YOUNG , HUMBLET PIERRE A
Abstract: A device and method for precoding a sequence of analog levels transmitted over an analog channel to a quantization device, wherein the analog channel modifies the transmitted analog levels, including: a mapping device for mapping data bits to be transmitted to a sequence of equivalence classes, wherein each equivalence class contains one or more constellation points; a constellation point selector interconnected to the mapping device which selects a constellation point in each equivalence class to represent the data bits to be transmitted and which transmits a level that produces the selected constellation point at an input to the quantization device; and a filter device, operably coupled to the constellation point selector, which receives at its input previously transmitted levels and provides its output to the constellation point selector; wherein the filter device has a filter response which is based on the previously transmitted levels and a target response, and the target response is adapted using an analog channel error signal, the selected constellation point at an input to the quantization device.
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3.发明专利
公开(公告)号：AU3322301A
公开(公告)日：2001-08-14
申请号：AU3322301
申请日：2001-02-01
Applicant: MOTOROLA INC
Inventor： MAURER PATRICK , KIM DAE-YOUNG , MEHRABANZAD SEPEHR
IPC: H04L27/00 , H04B7/005 , H04B14/04 , H04L25/49 , H04M11/00 , H04B14/06 , H04B1/38 , H04L5/16 , H04L25/34
Abstract: In a PCM modem system in which equivalence classes are used to communicate information from a transmitter to a receiver, a method is provided to solve the problem of 180° phase reversals in the communications channel which result in a garbled transmission. This is accomplished by remapping the equivalence classes into a form that can be differentially encoded and decoded such that equivalence class identity is not lost during a phase reversal of the channel.
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公开(公告)号：AU6938000A
公开(公告)日：2001-04-10
申请号：AU6938000
申请日：2000-08-25
Applicant: MOTOROLA INC
Inventor： MEHRABANZAD SEPEHR , KIM DAE-YOUNG , PILOZZI JOHN
Abstract: In order to achieve reliable and efficient communication over public switched telephone networks (PSTN), voice-band modems utilize sophisticated start-up procedures. This invention involves a start-up procedure that allows an analog modem and a digital modem to establish a dial-up connection that utilizes PCM modulation in both upstream and downstream directions for data transmission.
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公开(公告)号：AU1586799A
公开(公告)日：1999-07-19
申请号：AU1586799
申请日：1998-11-13
Applicant: MOTOROLA INC
Inventor： EYUBOGLU M VEDAT , HUMBLET PIERRE A , KIM DAE-YOUNG
Abstract: A device and method for precoding a sequence of analog levels transmitted over an analog channel to a quantization device, wherein the analog channel modifies the transmitted analog levels, including: a mapping device for mapping data bits to be transmitted to a sequence of equivalence classes, wherein each equivalence class contains one or more constellation points; a constellation point selector interconnected to the mapping device which selects a constellation point in each equivalence class to represent the data bits to be transmitted and which transmits a level that produces the selected constellation point at an input to the quantization device; and a filter device, operably coupled to the constellation point selector, which receives at its input previously transmitted levels and provides its output to the constellation point selector; wherein the filter device has a filter response which is based on the previously transmitted levels and a target response, and the target response is adapted using an analog channel error signal, the selected constellation point at an input to the quantization device.
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Patent Agency Ranking
公开(公告)号：CA2317547A1
公开(公告)日：1999-07-08
申请号：CA2317547
申请日：1998-11-13
Applicant: MOTOROLA INC
Inventor： KIM DAE-YOUNG , HUMBLET PIERRE A
Abstract: A transmitter in an analog pulse code modulation (PCM) modem (12) which transmits analog levels over an analog channel (18) to produce constellation points at a quantization device (26), wherein the constellation points correspond to groups of data bits to be transmitted to a digital PCM modem (28), the transmitter includes: a transmitter device which selects for each group of data bits to be transmitted a constellation point corresponding to the group of data bits and transmits over the analog channel a level that will produce at the input to the quantization device the selected constellation point; wherein the constellation points are chosen from a transmit constellation consisting of a plurality of non-uniformly spaced constellation points that have substantially equivalent, minimized error probability, constellation point to constellation point.
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公开(公告)号：CA2398487C
公开(公告)日：2010-04-20
申请号：CA2398487
申请日：2001-02-01
Applicant: MOTOROLA INC
Inventor： KIM DAE-YOUNG , MEHRABANZAD SEPEHR , PILOZZI JOHN
IPC: H04B1/38 , H04L25/03 , H04B1/00 , H04B1/10 , H04B3/04 , H04B3/06 , H04B7/005 , H04B14/04 , H04L25/49
Abstract: A method and apparatus is provided for controlling the transmit power of an analog modem (12) when the transmit power does not match the desired transmit power level, thus conforming to FCC regulations on transmit power and/or eliminating non-linearities associated with higher than required power levels and loss of signal-to-noise ratio and concomitant at loss of data rate if the transmit power levels are less than that desired. The power level (26) at the analog modem (12) is sensed to ascertain if it is not at the desired transmit power level (28), with adjustment being provided by transmitting the desired change (30) in the transmit power level to the digital modem (18), whereupon mapping parameters (34, 36) are redefined by adjusting the number of equivalence classes, thus to adjust transmit power at analog modem (12).
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公开(公告)号：DE69839814D1
公开(公告)日：2008-09-11
申请号：DE69839814
申请日：1998-11-13
Applicant: MOTOROLA INC
Inventor： KIM DAE-YOUNG , HUMBLET PIERRE A
Abstract: A transmitter in an analog pulse code modulation (PCM) modem (12) which transmits analog levels over an analog channel (18) to produce constellation points at a quantization device (26), wherein the constellation points correspond to groups of data bits to be transmitted to a digital PCM modem (28), the transmitter includes: a transmitter device which selects for each group of data bits to be transmitted a constellation point corresponding to the group of data bits and transmits over the analog channel a level that will produce at the input to the quantization device the selected constellation point; wherein the constellation points are chosen from a transmit constellation consisting of a plurality of non-uniformly spaced constellation points that have substantially equivalent, minimized error probability, constellation point to constellation point.
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9.发明专利
公开(公告)号：AU4963501A
公开(公告)日：2001-12-11
申请号：AU4963501
申请日：2001-03-30
Applicant: MOTOROLA INC
Inventor： KIM DAE-YOUNG , MEHRABANZAD SEPEHR , PILOZZI JOHN
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公开(公告)号：AU3322101A
公开(公告)日：2001-08-14
申请号：AU3322101
申请日：2001-02-01
Applicant: MOTOROLA INC
Inventor： PILOZZI JOHN , MEHRABANZAD SEPEHR , KIM DAE-YOUNG , BROWN WILLIAM LESLIE
Abstract: In a PCM modem system, a method and apparatus for optimizing the fractional sampling phase offset in the upstream direction to maximize the upstream data rate utilizes a probing signal from the analog modem generated during startup and having at least two distinct phases of a pure tone, with the probing signal being detected at the digital modem where an optimum sampling phase value is calculated. From this calculated value, a signal representing the appropriate amount to delay the input data stream is transmitted back to the analog modem for adjustment of the fractional sampling phase so that the fractional sampling phase offset at the central office quantizer is optimized.
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