Method of improving modem performance by controlling transmitted power of modem, and modem implementing the same

Claim 3

A method according to claim 1, wherein: said transmitting power is adjusted to a substantially optimal level.

Claim 4

A method according to claim 1, further comprising: calibrating at least one of said first and second modems, wherein said calibrating step is used in said step of adjusting.

Claim 5

A method according to claim 3, wherein: said step of calibrating comprises generating a table relating an adjustment in transmitting power or a desired transmitting power to said measured signal/noise ratio and said IMD.

Claim 6

A method according to claim 4, wherein: said step of generating a table comprises testing a modem substantially similar to said modem to be calibrated at different power levels over channels having different IMD levels and different signal/noise ratios, comparing the error rates obtained for each of said channels at said different power levels, and assigning and storing a plurality of either power level indicators or power drop indicators, each power level indicator or power drop indicator relating to a preferred transmitting power for a channel exhibiting a particular combination of IMD level and signal/noise ratio.

Claim 7

A method according to claim 1, wherein: said step of adjusting comprises adjusting said transmitting power to a power level equal to said maximum permissable power minus a power defined by a function of said IMD.

Claim 8

A method according to claim 6, wherein: said function of said IMD is [(42-x)/2] dB, wherein x is a third harmonic of said IMD.

Claim 9

A method according to claim 6, wherein: said function of said IMD changes based on said signal/noise ratio measured.

Claim 10

A method according to claim 8, wherein: said function of said IMD is [(42-x)/2] dB when said signal/noise ratio is greater than approximately 30 dB, and said function of said IMD is [(42-x)/4] dB when said signal/noise ratio is less than approximately 30 dB, wherein x is a third harmonic of said IMD.

Claim 13

A method according to claim 10, wherein: said transmitting power is adjusted to a substantially optimal level.

Claim 14

A method according to claim 11, wherein: said step of calibrating comprises generating a table relating an adjustment in transmitting power or a desired transmitting power to said measured signal/noise ratio and said IMD.

Claim 15

A method according to claim 10, further comprising: e) calibrating at least one of said first and second modems, wherein said calibrating step is used in said step of adjusting.

Claim 16

A method according to claim 13, wherein: said step of generating a table comprises testing a modem substantially similar to said modem to be calibrated at different power levels over channels having different IMD levels and different signal/noise ratios, comparing the error rates obtained for each of said channels at said different power levels, and assigning and storing a plurality of either power level indicators or power drop indicators, each power level indicator or power drop indicator relating to a preferred transmitting power for a channel exhibiting a particular combination of IMD level and signal/noise ratio.

Claim 17

A method according to claim 10, wherein: said step of adjusting comprises adjusting said transmitting power to a power level equal to said maximum permissable power minus a power defined by a function of said IMD.

Claim 18

A method according to claim 15, wherein: said function of said IMD is [(42-x)/2] dB, wherein x is a third harmonic of said IMD.

Claim 19

A method according to claim 15, wherein: said function of said IMD changes based on said signal/noise ratio measured.

Claim 20

A method according to claim 17, wherein: said function of said IMD is [(42-x)/2] dB when said signal/noise ratio is greater than approximately 30 dB, and said function of said IMD is [(42-x)/4] dB when said signal/noise ratio is less than approximately 30 dB, wherein x is a third harmonic of said IMD.

Claim 21

A method according to claim 10, wherein: said measuring step is accomplished during at least one of a probing procedure and a handshake procedure.

Claim 22

A method according to claim 19, wherein: said measuring step is further accomplished during transmission of data from said first modem to said second modem.

Claim 25

A method according to claim 21, wherein: said step of comparing is accomplished at said second modem, and said second modem sends information to said first modem to indicate which of said first and second power levels is preferred.

Claim 26

A method according to claim 21, wherein: said second modem sends to said first modem information relating to said first and second error rates, and said first modem compares said error rate information, in order to detemine which of said first and second power levels is preferred.

Claim 27

A method according to claim 21, further comprising: sending third signals from said first modem over said channel to said second modem at a third power level, and measuring at said second modem the data transmission error rates relating to said third signals being transmitted over said channel, wherein said comparing step includes comparing said data transmission error rates relating to said third signals with said data transmission error rates relating to said first and second signals.

Claim 28

A method according to claim 24, further comprising: said step of comparing is accomplished at said second modem, and said second modem sends information to said first modem to indicate which of said first, second, and third power levels is preferred.

Claim 29

A method according to claim 24, wherein: said second modem sends to said first modem information relating to said first, second and third error rates, and said first modem compares said error rate information, in order to detemine which of said first, second, and third power levels is preferred.

Claim 32

A method according to claim 27, wherein: steps a) through d) are repeated until either an acceptable error rate threshold is met or an optimum transmitting power is found.

Claim 33

In a first modem having transmitter means for transmitting signals over a channel including a telephone line over which said signals are transmitted to a second modem which has measurement means for making measurements related to the data transmission error rate related to said signals which were transmitted over said channel, an improvement in said first modem comprising: attenuator means coupled with said transmitter means for adjusting the transmitting power of said transmitter means to a level below a maximum permissable level for said channel in response to the measurements made by said measurement means of said second modem in order to reduce the error rate of the data transmission from said first modem over said channel, wherein said measurements related to the error rate comprise measurements of the signal/noise ratio and intermodulation distortion (IMD) of said signals which were transmitted over said channel, wherein said error rate is a function of at least both said signal/noise ratio and said IMD.

Claim 34

In a first modem having transmitter means for transmitting signals over a channel including a telephone line over which said signals are transmitted to a second modem which has measurement means for making measurements related to the data transmission error rate related to said signals which were transmitted over said channel, an improvement in said first modem comprising: attenuator means coupled with said transmitter means for adjusting the transmitting power of said transmitter means to a level below a maximum permissable level for said channel in response to the measurements made by said measurement means of said second modem in order to reduce the error rate of the data transmission from said first modem over said channel, wherein said measurements related to the error rate comprise measurements of the signal/noise ratio and intermodulation distortion (IMD) of said signals which were transmitted over said channel, wherein said error rate is a function of at least both said signal/noise ratio and said IMD.

Claim 35

The improvement of claim 29, wherein: said first modem further comprises a digital processing means for modulating a data signal, and said attenuator means comprises a digital multiplier for multiplying said modulated data signal so as to adjust the power of said modulated data signal, wherein said first modem is provided with a digital to analog converter for converting said modulated data signal into an analog data signal.

Claim 36

The improvement of claim 29, wherein: said first modem further comprises a digital to analog converter for converting modulated digital signals into analog signals, and said attenuator means comprises an analog circuit means for adjusting the power of said analog sigals.

Claim 37

The improvement of claim 29, wherein: said first modem further comprises receiver means for receiving a control signal from said second modem regarding a desired power at which said transmitter means of said first modem should transmit data to said second modem over said channel.

Claim 38

The improvement of claim 32, wherein: said first modem further comprises processor means for receiving said control signal from said receiver means, and sending information to said attenuator means for adjusting the transmitting power of said transmitter means.

Claim 39

The improvement of claim 33, wherein: said measurements related to the error rate comprise measurements of the signal/noise ratio and intermodulation distortion (IMD) of said signals which were transmitted over said channel, wherein said error rate is a function of at least both said signal/noise ratio and said IMD, and said first modem further comprises measurement means for measuring the signal/noise ratio and intermodulation distortion (IMD) of second signals which were transmitted over a second channel, and memory means for storing a table relating an adjustment in transmitting power or a desired transmitting power to said measured signal/noise ratio and said IMD of said second signals.

Claim 40

The improvement of claim 34, wherein: said first modem further comprises measurement means for measuring the signal/noise ratio and intermodulation distortion (IMD) of second signals which were transmitted over a second channel, and said processor means further comprises calculation means for calculating a transmitting power adjustment.

Claim 41

The improvement of claim 35, wherein: said transmitting power adjustment is calculated according to a function of said IMD.

Claim 42

The improvement of claim 36, wherein: said function of IMD is [(42-x)/2] dB, wherein x is a third harmonic of said IMD.

Claim 43

The improvement of claim 36, wherein: said function of said IMD changes based on said signal/noise ratio measured.

Claim 44

In a first modem having transmitter means and receiver means, said transmitter means for transmitting signals over a channel having a telephone line over which said signals are transmitted to a second modem which has means for measuring the data transmission error rate related to said signals which were transmitted over said channel, and said receiver means for receiving signals from said second modem, an improvement in said first modem comprising: attenuator means coupled with said receiver means and said transmitter means, for adjusting the transmitting power of said transmitter means to send first and second signals of different power levels to said second modem, wherein said second modem measures first and second data transmission error rates related to said first and second signals, and one of said first and second modems compares said data transmission error rates to each other to find the power level having the lower data transmission error rates, and means for adjusting the transmitting power of said transmitter means to a level below a maximum permissible level for said channel in response to the power level of the signals having the lower data transmission error rates in order to reduce the error rate of the data transmission from said first modem over said channel.

Claim 45

In a first modem having transmitter means and receiver means, said transmitter means for transmitting signals over a channel having a telephone line over which said signals are transmitted to a second modem which has means for measuring the data transmission error rate related to said signals which were transmitted over said channel, and said receiver means for receiving signals from said second modem, an improvement in said first modem comprising: attenuator means coupled with said receiver means and said transmitter means, for adjusting the transmitting power of said transmitter means to send first and second signals of different power levels to said second modem, wherein said second modem measures first and second data transmission error rates related to said first and second signals, and one of said first and second modems compares said data transmission error rates to each other to find the power level having the lower data transmission error rates, and means for adjusting the transmitting power of said transmitter means to a level below a maximum permissible level for said channel in response to the power level of the signals having the lower data transmission error rates in order to reduce the error rate of the data transmission from said first modem over said channel.

Claim 46

The improvement of claim 39, wherein: said second modem includes comparison means for comparing said first and second data transmission error rates, wherein said second modem sends information to said first modem to indicate which of said first and second power levels is preferred.

Claim 47

The improvement of claim 39, wherein: said second modem sends to said first modem information relating to said first and second data transmission error rates, and said second modem comprises comparison means for comparing said data transmission error rate information.

Claim 48

In a first modem having transmitter means and receiver means, said transmitter means for transmitting signals over a channel including a telephone line over which said signals are transmitted to a second modem which has means for measuring at least one of the data transmission error rate related to said signals which were transmitted over said channel and the quality of points in a constellation which said signals represent, and said receiver means for receiving signals from said second modem, an improvement in said first modem comprising: attenuator means coupled to said receiver means and said transmitter means, for adjusting the transmitting power of said transmitter means to send signals of different power levels to said second modem in response to control signals received by said receiver means of said first modem from said second modem, wherein said second modem measures one of the data transmission error rates related to said signals and quality of said points in said constellation and sends to said first modem said control information for adjusting the transmitting power of said transmitter means to a level below a maximum permissable level for said channel, and after said transmitter power is adjusted to send second signals at a second power level, said second modem measures one of a second data transmission error rate related to said second signals and a second quality of points in said constellation and sends second control signals to further adjust the transmitting power of said transmitter means to another level below said maximum permissable level, wherein in adjusting the transmitting power in order to reduce the data transmission error rate, the power may be adjusted up or down in response to an increase in measured error rate.

Claim 49

In a first modem having transmitter means and receiver means, said transmitter means for transmitting signals over a channel including a telephone line over which said signals are transmitted to a second modem which has means for measuring at least one of the data transmission error rate related to said signals which were transmitted over said channel and the quality of points in a constellation which said signals represent, and said receiver means for receiving signals from said second modem, an improvement in said first modem comprising: attenuator means coupled to said receiver means and said transmitter means, for adjusting the transmitting power of said transmitter means to send signals of different power levels to said second modem in response to control signals received by said receiver means of said first modem from said second modem, wherein said second modem measures one of the data transmission error rates related to said signals and quality of said points in said constellation and sends to said first modem said control information for adjusting the transmitting power of said transmitter means to a level below a maximum permissable level for said channel, and after said transmitter power is adjusted to send second signals at a second power level, said second modem measures one of a second data transmission error rate related to said second signals and a second quality of points in said constellation and sends second control signals to further adjust the transmitting power of said transmitter means to another level below said maximum permissable level, wherein in adjusting the transmitting power in order to reduce the data transmission error rate, the power may be adjusted up or down in response to an increase in measured error rate.