摘要:
A method of generating a data constellation at a client modem is provided whereby an optimum distance between data constellation data points may be calculated for a predetermined, acceptable error probability. An iterative process may be carried out using proposed data constellations which may be used to provide factors for calculating corrected constellations. Once a constellation is generated to satisfy the required probability of error, the constellation may be re-evaluated using CRC errors and detected noise variance at the client modem. Based upon predetermined levels of noise variance and CRC error, the constellation may be regenerated to operate at either a higher bit rate or a lower bit rate.
摘要:
A technique is proposed to accurately estimate the Network CODEC levels for each PCM code a server modem generates. These levels are affected by the digital impairments such as Digital attenuation PAD in the trunk, the Robbed Bit Signaling, the type of CODEC (μ-law or a-law—or non standard), and by analog impairments such as loop distortion, noise, inter-modulation distortion, echo. At client modem equalizer output good estimates for these levels are derived. By detecting RBS pattern of the trunk, and using averages of decode levels of similar RBS slots, more accurate data points are obtained. By further replacing these levels with the closest CODEC receive levels, good accuracy is obtained. Non-monotonic points are detected and eliminated. An upper limit is set for constellation points to avoid saturation of the receiver. IMD correction is applied to the decode levels. Ideal points that are not signaled, are added if possible. When PAD-detection or Codec detection fails, PAD is set to 0 dB and the constellation is based on originally received and averaged data points. Techniques are presented for V.90 type modem constellation generation.
摘要:
A technique is proposed to accurately estimate the Network CODEC levels for each PCM code a server modem generates. These levels are affected by the digital impairments such as Digital attenuation PAD in the trunk, the Robbed Bit Signaling, the type of CODEC (&mgr;-law or a-law—or non standard), and by analog impairments such as loop distortion, noise, inter-modulation distortion, echo. At client modem equalizer output good estimates for these levels are derived. By detecting RBS pattern of the trunk, and using averages of decode levels of similar RBS slots, more accurate data points are obtained. By further replacing these levels with the closest CODEC receive levels, good accuracy is obtained. Non-monotonic points are detected and eliminated. An upper limit is set for constellation points to avoid saturation of the receiver. IMD correction is applied to the decode levels Ideal points that are not signaled, are added if possible . When PAD-detection or Codec detection fails, PAD is set to 0 dB and the constellation is based on originally received and averaged data points. Techniques are presented for V.90 type modem constellation generation.
摘要:
A technique for modifying communication operational parameters using fast, low complexity, accurately calculated SNR values. Techniques may improve upon prior art by calculating SNR values in a more time efficient and accurate manner in time domain. An agent may be implemented to calculate SNR values and either store or use the SNR values to modify operational parameters in communicative system.
摘要:
A technique for modifying communication operational parameters using fast, low complexity, accurately calculated SNR values. Techniques may improve upon prior art by calculating SNR values in a more color noise insensitive manner in the frequency domain. An agent may be implemented to calculate SNR values and either store or use the SNR values to modify operational parameters in communicative system.
摘要:
Embodiments of the invention provide methods for determining the characteristics of a local loop using the multi-carrier tones of a DSL activation process. For one embodiment, one or more sets of downstream multi-carrier tones of a digital subscriber line activation process are received at an extended voice-band modem and are capable of transmitting upstream multi-carrier tones of the digital subscriber line activation process over a local loop. The downstream carrier tones and the upstream carrier tones are folded into a first multi-tone signal and a second multi-tone signal, respectively, each having a plurality of component signals within the spectrum band of the extended voice-based modem. The total signal power of the first multi-tone signal is divided by the power of one of the plurality of component signals of the second multi-tone signal to determine a ratio value. The ratio value is used to determine a characteristic of the local loop.
摘要:
In one embodiment, a method is provided. The method of this embodiment provides receiving a communication having a data sample set, generating a selective data sample set based, at least in part, on the data sample set, and using the selective data sample set to update a training algorithm using an updating algorithm.
摘要:
Embodiments of the invention provide methods for determining the characteristics of a local loop using the multi-carrier tones of a DSL activation process. For one embodiment, one or more sets of downstream multi-carrier tones of a digital subscriber line activation process are received at an extended voice-band modem and are capable of transmitting upstream multi-carrier tones of the digital subscriber line activation process over a local loop. The downstream carrier tones and the upstream carrier tones are folded into a first multi-tone signal and a second multi-tone signal, respectively, each having a plurality of component signals within the spectrum band of the extended voice-based modem. The total signal power of the first multi-tone signal is divided by the power of one of the plurality of component signals of the second multi-tone signal to determine a ratio value. The ratio value is used to determine a characteristic of the local loop.
摘要:
A technique for modifying communication operational parameters using fast, low complexity, accurately calculated SNR values. Techniques may improve upon prior art by calculating SNR values in a more color noise insensitive manner in the frequency domain. An agent may be implemented to calculate SNR values and either store or use the SNR values to modify operational parameters in communicative system.