Impulse noise management

#This invention generally relates to communication systems. In particular, an exemplary aspect of this invention relates to impulse noise protection adaptation. Another exemplary aspect of this invention relates to impulse noise length and period determination and use thereof for impulse noise protection adaptation.

#Communications systems often operate in environments that produce impulse noise. Impulse noise is a short-term burst of noise that is higher than the normal noise that typically exists in a communication channel. For example, DSL systems operate on telephone lines and experience impulse noise from many external sources including telephones, AM radio, HAM radio, other DSL services on the same line or in the same bundle, other equipment in the home, etc. It is standard practice for communications systems to use interleaving in combination with Forward Error Correction (FEC) to correct the errors caused by impulse noise. Standard initialization procedures in ADSL and VDSL systems are designed to optimize performance (data rate/reach) in the presence “stationary” crosstalk or noise. Impulse noise protection is handled with interleaving and FEC, but the current xDSL procedure at least does not provide specific states to enable training for the selection of the appropriate interleaving and FEC parameters.

#An exemplary problem associated with traditional communication systems is that they use traditional Signal to Noise Ratio (SNR) measurement techniques to determine the SNR of the channel. These traditional techniques assume that the noise is stationary and does not contain non-stationary components such as impulse noise. The most common method for measuring the SNR is to calculate the mean-square error of the received signal based on a known transmitted signal, which is described in the ADSL series of ITU G.992.x standards and the VDSL series of ITU G.993.x standards, which are incorporated herein by reference in their entirety. These traditional methods for measuring SNR do not correctly measure the impact of impulse noise and do not have the noise capability to determine how the system should be configured to handle impulse noise.

#The features of this invention will be described in relation to the figures, wherein:

#FIG. 1 is a functional block diagram illustrating an exemplary impulse noise adaptation system according to this invention;

#FIG. 2 illustrates an exemplary initialization state machine that includes an INPTraining state according to this invention;

#The exemplary embodiments of this invention will be described in relation to adapting impulse noise parameters as well as measuring impulse noise length and repetition period within an xDSL environment. However, it should be appreciated that, in general, the systems and methods of this invention can be applied and will work equally well with any type of communication system in any environment.

#The exemplary systems and methods of this invention will be described in relation to xDSL modems and associated communication hardware, software, and communication channels. However, to avoid unnecessarily obscuring the present invention, the following description omits well-known structures and devices that may be shown in block diagram form or otherwise summarized.

#For purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the present invention. It should be appreciated however, that the present invention may be practiced in a variety of ways beyond the specific details set forth herein. For example, the systems and methods of this invention can generally be applied to any type of system within any environment in which the impulse noise length and/or period is desired, or for which impulse noise adaptation is desired.