High speed quantization-level-sampling modem with equalization arrangement

A high speed quantization-level-sampling (QLS) modem communications system for equalizing loop signals which comprises:

• (a) a quantizing-rule-based telephone system network which utilizes a transmission system wherein analog to digital (A/D) conversion of first loop signals and digital to analog (D/A) conversion of second loop signals are based on a known quantizing rule with the predetermined .mu.-law quantizing levels, and includes:
• a plurality of coder/decoder (codec) stations for analog to digital and digital to analog conversion of the first and second loop signals, respectively, using .mu.-law quantizing levels;
• and
• a switched digital network operatively connected to the plurality of coder/decoder stations for transmitting the A/D and D/A converted signals among the plurality of coder/decoder stations;
• and,
• (b) a plurality of modems operatively connected to the quantizing-rule-based telephone system network, each such modem having a transmitter component and a receiver component for transmitting and receiving loop signals through the quantizing-rule-based telephone system network which utilizes the transmission system wherein A/D conversion of received loop signals and D/A conversion of input data signals to output loop signals are based on the known quantizing rule with the predetermined .mu.-law quantizing levels, the transmitter component including:
• transmitting means within the transmitter component for D/A converting the input data signals to D/A output signals as the output loop signals using a channel symbol alphabet which is equivalent to the predetermined .mu.-law quantizing levels of a quantizing-rule-based system network, and for transmitting the output loop signals to the at least one codec, the transmitting means including:
• an encoder for encoding input data signals;
• a plurality of transmitter equalizers for equalizing the encoded input data signals as equalized transmitter signals;
• an adder for adding the equalized transmitter signals to a sum signals;
• an emission mask filter for filtering the sum signal;
• and
• a D/A converter operatively connected to the quantizing-rule-based telephone system network for converting the sum signal using the channel symbol alphabet which is equivalent to the predetermined .mu.-law quantizing levels of a quantizing-rule-based system network to generate the output loop signals equalized using the known quantizing rule with the predetermined .mu.-law quantizing levels, and for transmitting the output loop signals over a first channel to a first codec;
• and,
• receiving means within the receiver component for receiving the received loop signals from the at least one codec transmitted over a second channel, with the received loop signals having the channel symbol alphabet which is equivalent to the predetermined .mu.-law quantizing levels of a quantizing-rule-based system network, and for A/D converting the received loop signals;
• the receiving means including:
• an A/D converter operatively connected to the quantizing-rule-based telephone system network for converting the received loop signals from a second codec to an A/D converted signal equalized using the known quantizing rule with the predetermined .mu.-law quantizing levels and the channel symbol alphabet which is equivalent to the predetermined .mu.-law quantizing levels of the quantizing-rule-based system network;
• a plurality of receiver equalizers for generating a received samples from the A/D converted signal;
• a plurality of slicers for processing the received samples to generate output symbol streams;
• and
• a decoder for decoding the output symbol streams.