Abstract:
A device coupled to a noisy channel having periodic impulse noise in a network may estimate an effective signal to noise ratio (SNR) by receiving a packet of symbols. The device may determined a number of bad symbols N(bad) ratio in the packet due to interference and a remaining plurality of good symbols in the packet. An SNR value may be computed based on only the plurality of good symbols in the packet of symbols to form an SNR(good) value. An SNR correction value (SNR(offset)) may be determined as a function of the N(bad) ratio and the SNR(good) value. An effective SNR value may then be calculated by adjusting the SNR(good) value according to SNR(offset).
Abstract:
An orthogonal frequency division multiplexing (OFDM) receiver includes detection logic, offset generation logic, tone erasure logic, and correction generation logic. The detection logic is configured to detect a signal containing a block of samples that includes a narrowband interferer from a communication channel. The offset generation logic is configured to align a frequency of the narrowband interferer to a center of a subcarrier frequency of the communication channel to produce an offset signal thereby introducing inter-carrier interference (ICI). The tone erasure logic is configured to remove the subcarrier frequency from the offset signal to produce an interferer erased offset signal. The correction generation logic is configured to remove the ICI to produce an interferer erased signal.
Abstract:
Apparatus (and related methods) for a power line communication network include a processor configured to receive beacons over a communication interface. The processor determines a link quality indicator (LQI) for each received beacon and ignores the beacons for at most a predetermined maximum number of beacon receptions when each LQI is below a threshold. The processor responds to a received beacon if the LQI for such received beacon exceeds the threshold or if a predetermined maximum number of beacons have been received with LQIs below the threshold.
Abstract:
In a method for transmitting frames of data across a physical media that has a selective frequency response, a packet of data bytes is received by a media access (MAC) layer of a communication protocol from a local application for transmission to a remote receiver. The packet of data bytes is padded to from a padded packet of data bytes having a predetermined frame length, wherein the predetermined frame length is a frame length that is predetermined to provide correct transmission of a frame of data across the physical media that has a selective frequency response. The padded packet of data bytes is encoded by a physical (PHY) layer of the communication protocol to form multiple tone symbols. The multi-tone symbols are then transmitted on the physical media to the remote receiver.