Abstract: System and method for partitioning a DSLAM network. In this regard, one such network can be broadly summarized by a representative communication system comprising a digital subscriber line access multiplexer (DSLAM) that is communicatively coupled on its line-side to a high-speed digital link. The DSLAM is communicatively coupled through the high-speed digital link with the trunk side of a remote line access unit (RLAU). The RLAU is communicatively coupled on its line-side to a first digital subscriber line (DSL).

Abstract: A system and method for increasing payload in a data transmission system. In architecture, the system comprises a modulation device configured to modulate data bins to produce bin-clusters, a mechanism to load the bin-clusters with data, a transmitter configured to transmit the loaded bin-clusters, a receiver configured to receive the transmitted bin-clusters, and a demodulation device configured to extract data from the received bin-clusters. The method steps comprise the steps of modulating data bins to produce bin-clusters, loading the bin-clusters with data, transmitting the loaded bin-clusters, receiving the transmitted bin-clusters, and extracting data from the received bin-clusters.

Abstract: A finite impulse response (FIR) filter characterization is performed using a modified least means squares approach that updates values of FIR filter taps as groups of taps, periodically. For the taps updated for a current input signal sample, future convolution values for future input signal samples are computed and also a partial estimate of the signal response is computed. The expected response is then computed by summing the partial estimate signal response and other partial estimates of the signal response which are computed from future convolution, missed tap update convolution and normalizes error signal values which have been previously computed at past input signal samples and stored in memory.

Abstract: In accordance with the present invention, local loop testing in an echo canceller based modem is provided in a manner in which proper operation of both the receiver and echo canceller can be assessed simultaneously. Specifically, the modem includes means for generating data and interfering symbol sequences and for applying the interfering sequence to both the echo canceller and the modem transmitter, while applying the data sequence only to either the transmitter or the echo canceller. During closed loop testing, the modem connection to the transmission line is opened, and a portion of the output of the modem transmitter is applied to the modem receiver via a leakage path through the hybrid. The received symbol is subtracted from the echo canceller output, resulting in application to the receiver of only a version of the data symbol sequence. Advanced knowledge of the characteristics of the data symbol sequence allows proper receiver operation to be verified.

Abstract: A modem capable of achieving essentially 9600 bit per second information transfer rate through the switched telephone network. The high bit rate is achieved notwithstanding the variations in the characteristics of the switched telephone network by phase and amplitude modulating a plurality of sub-carriers at a relatively low baud rate. Correlation detection is employed at the receiver to extract or demodulate the information contained in the various sub-carriers. To allow correlation detection with orthogonal signals, each of the sub-carriers is harmonically related to a fundamental which fundamental is, however, slightly higher than the baud rate. This allows the receiver to delay correlation for a "gap" time, which reduces the effect of transients produced by modulation and also provides greater tolerance to inter-symbol distortion.