Enhanced CIMT coding system and method with automatic word alignment for simplex operation

A data transmission system comprising:

• a conditional invert master transition (CIMT) encoder for encoding a digital data input signal to a balanced stream of digital data and transmitting said data over a communications link in a simplex mode of transmission;
• multiplexer means for (a) receiving said stream of CIMT encoded digital data and data from a local source, and (b) providing an intermediate output signal in response thereto;
• a CIMT decoder for analyzing a first portion of said intermediate output signal to identify predetermined pattern of data, the CIMT decoder including (i) means for checking for proper word alignment, (ii) means, operative if proper word alignment is not found, for performing a bit slip to slip word alignment relative to a bit rate clock, and (ii) means for repeating operation of the means (i) and (ii) until proper word alignment is found;
• and
• a state machine:
• (a) for commanding said multiplexer to output said received digital data to said decoder in accordance with in a first state in response to a detection of said predetermined pattern of data in said received digital data by said CIMT decoder;
• and
• (b) for commanding said multiplexer to output other data to said CIMT decoder in accordance with a second state in response to a failure of said CIMT decoder to detect said predetermined pattern of data in said received digital data.

A data transmission system comprising:

• a transmitter having a conditional invert master transition (CIMT) encoder for encoding a digital data input signal to a balanced stream of digital data and transmitting said data over a communications link in a simplex mode of transmission, said CIMT encoder including means for scrambling a flag bit to provide a scrambled flag bit;
• and
• a receiver having:
• multiplexer means for receiving said stream of conditional invert master transition encoded digital data and data from a local source and providing an intermediate output signal in response thereto;
• a CIMT decoder for analyzing a first portion of said intermediate output signal to identify predetermined pattern of data, the CIMT decoder including (i) means for checking for proper word alignment, (ii) means, operative if proper word alignment is not found, for performing a bit slip to slip word alignment relative to a bit rate clock, and (ii) means for repeating operation of the means (i) and (ii) until proper word alignment is found;
• means for receiving and descrambling said scrambled flag bit to provide a descrambled flag bit;
• and
• a state machine:
• (a) for commanding said multiplexer to output said received digital data to said decoder in accordance with in a first state in response to a detection of said predetermined pattern of data in said received digital data by said CIMT decoder, and
• (b) for commanding said multiplexer to provide output other data to said CIMT decoder in accordance with a second state in response to (i) a failure of said CIMT decoder to detect said predetermined pattern of data in said received digital data, or (ii) detection of a static descrambled flag bit.

A data reception method comprising the steps of:

• receiving a stream of digital data;
• analyzing successive portions of said data to identify a predetermined pattern of data, the step of analyzing including (i) checking for proper word alignment, (ii) if proper word alignment is not found, performing a bit slip to slip word alignment relative to a bit rate clock, and (ii) repeating steps (i) and (ii) until proper word alignment is found;
• and
• outputting said received digital data in response to a detection of said predetermined pattern of data in said received digital data and for outputting other data in response to a failure to detect said predetermined pattern of data in said received digital data.