Method and apparatus for determining transmit power levels for data transmission and reception
First Claim
1. A method of determining a power level for data transmission and reception, from a transmitted probe signal received via a channel, the transmitted probe signal having a sequence of a plurality of tones having predetermined frequency, amplitude and phase characteristics, the transmitted probe signal having a first power level and a second power level, the transmitted probe signal received for a minimum duration for each of the first and second power levels to form a received probe signal having a plurality of sets of received probe tones, each set of received probe tones having a plurality of probe tone frequencies, the method comprising:
- (a) determining an average probe signal level for each probe tone frequency of the received probe signal for the first power level, to form a first set of probe signal average power levels, and for the second power level, to form a second set of probe signal average power levels;
(b) determining an average noise level for a plurality of noise frequencies for the first power level, to form a first set of average noise levels, and for the second power level, to form a second set of average noise levels;
(c) determining a harmonic content parameter of the received probe signal, for the first power level and for the second power level;
(d) determining a receive signal power parameter from the second set of probe signal average power levels;
(e) determining a plurality of signal to distortion ratios, each of the plurality of signal to distortion ratios corresponding to a symbol rate and carrier frequency combination from a plurality of combinations of symbol rates and carrier frequencies, to form a set of signal to distortion ratios;
(f) determining a proportional noise parameter from the set of signal to distortion ratios;
(g) determining a signal to distortion threshold parameter, from the set of signal to distortion ratios; and
(h) determining a transmit power level from the signal to distortion threshold parameter, the harmonic content parameter, the receive signal power parameter, and the proportional noise parameter.
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Accused Products
Abstract
An apparatus and method for a data communications device such as a modem (100, 101) to determine transmit power levels for data transmission and reception, from a received probe signal. The various embodiments utilizing a processor (108) or a digital signal processor (106) receive a probe signal, transmitted at two different power levels, which also typically contains noise and other distortions. The various method and apparatus embodiments then determine average signal levels (501), average noise levels (503), and a set of signal to distortion ratios corresponding to combinations of symbol rates and carrier frequencies. Parameters such as the receive signal power (509), the harmonic content (507), the proportional noise (511), and a signal to distortion ratio threshold (513) are utilized to determine a transmit power level (515).
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Citations
20 Claims
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1. A method of determining a power level for data transmission and reception, from a transmitted probe signal received via a channel, the transmitted probe signal having a sequence of a plurality of tones having predetermined frequency, amplitude and phase characteristics, the transmitted probe signal having a first power level and a second power level, the transmitted probe signal received for a minimum duration for each of the first and second power levels to form a received probe signal having a plurality of sets of received probe tones, each set of received probe tones having a plurality of probe tone frequencies, the method comprising:
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(a) determining an average probe signal level for each probe tone frequency of the received probe signal for the first power level, to form a first set of probe signal average power levels, and for the second power level, to form a second set of probe signal average power levels; (b) determining an average noise level for a plurality of noise frequencies for the first power level, to form a first set of average noise levels, and for the second power level, to form a second set of average noise levels; (c) determining a harmonic content parameter of the received probe signal, for the first power level and for the second power level; (d) determining a receive signal power parameter from the second set of probe signal average power levels; (e) determining a plurality of signal to distortion ratios, each of the plurality of signal to distortion ratios corresponding to a symbol rate and carrier frequency combination from a plurality of combinations of symbol rates and carrier frequencies, to form a set of signal to distortion ratios; (f) determining a proportional noise parameter from the set of signal to distortion ratios; (g) determining a signal to distortion threshold parameter, from the set of signal to distortion ratios; and (h) determining a transmit power level from the signal to distortion threshold parameter, the harmonic content parameter, the receive signal power parameter, and the proportional noise parameter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A modem for data transmission and reception, the modem having an initial training period for determining a transmit power level from a transmitted probe signal received via a channel, the transmitted probe signal having a sequence of a plurality of tones having predetermined frequency, amplitude and phase characteristics, the transmitted probe signal having a first power level and a second power level, the transmitted probe signal received for a minimum duration for each of the first and second power levels to form a plurality of sets of transmitted tones, the modem comprising:
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a data access arrangement coupleable to the channel to receive the transmitted probe signal, to form a received probe signal; an analog-digital converter coupled to the data access arrangement to sample and convert the received probe signal to form a plurality of sets of received probe tones; and a processor coupled to the analog-digital converter to receive the plurality of sets of received probe tones, the processor responsive to determine an average probe signal level for each tone frequency of the plurality of sets of received probe tones for the first power level, to form a first set of probe signal average power levels, and for the second power level, to form a second set of probe signal average power levels, and to determine an average noise level for a plurality of noise frequencies for the first power level, to form a first set of average noise levels, and for the second power level, to form a second set of average noise levels;
the processor further responsive to determine a harmonic content parameter of the plurality of sets of received probe tones, for the first power level and for the second power level and to determine a receive signal power parameter from the second set of probe signal average power levels;
the processor further responsive to determine a plurality of signal to distortion ratios, each of the plurality of signal to distortion ratios corresponding to a symbol rate and carrier frequency combination from a plurality of combinations of symbol rates and carrier frequencies, to form a set of signal to distortion ratios, and to determine a proportional noise parameter and a signal to distortion threshold parameter from the set of signal to distortion ratios; and
the processor further responsive to determine a transmit power level from the signal to distortion threshold parameter, the harmonic content parameter, the receive signal power parameter, and the proportional noise parameter. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification