Processing data in a coherent optical communication system

A processor comprising:

• a first analog-to-digital converter (ADC) configured to receive a first analog electrical data stream transmitted by a photonics module in a coherent optical communication system, and sample the first analog electrical data stream at a sampling rate that is nominally twice or greater than twice a symbol rate of the first analog electrical data stream and a second analog electrical data stream, which together represent a portion of an optical signal received by the photonics module, to convert the first analog electrical data stream into a first digital electrical data stream;
• a second ADC configured to receive the second analog electrical data stream transmitted by the photonics module, and sample the second analog electrical data stream at the sampling rate that is nominally twice or greater than twice the symbol rate of the first and second analog electrical data streams to convert the second analog electrical data stream into a second digital electrical data stream;
• a first digital filter configured to digitally filter the first digital electrical data stream to output a first filtered digital electrical data stream at an effective sampling rate that is less than the sampling rate and less than twice the symbol rate of the first and second analog electrical data streams, and greater than or equal to the symbol rate of the first and second analog electrical data streams;
• a second digital filter configured to digitally filter the second digital electrical data stream to output a second filtered digital electrical data stream at the effective sampling rate that is less than the sampling rate and less than twice the symbol rate of the first and second analog electrical data streams, and greater than or equal to the symbol rate of the first and second analog electrical data streams;
• and
• a downstream hardware unit that includes at least one component configured to process the first and second filtered digital electrical data streams at a rate that is substantially similar to the effective sampling rate to recover data in the optical signal received by the photonics module.

A network device comprising:

• a photonics module configured to receive an optical signal in a coherent optical communication system and transmit a first analog electrical data stream and a second analog data stream that together represent a portion of the optical signal;
• and
• a processor comprising:
• a first analog-to-digital converter (ADC) configured to receive the first analog electrical data stream, and sample the first analog electrical data stream at a sampling rate that is nominally twice or greater than twice a symbol rate of the first and second analog electrical data streams to convert the first analog electrical data stream into a first digital electrical data stream;
• a second ADC configured to receive the second analog electrical data stream, and sample the second analog electrical data stream at the sampling rate that is nominally twice or greater than twice the symbol rate of the first and second analog electrical data streams to convert the second analog electrical data stream into a second digital electrical data stream;
• a first digital filter configured to digitally filter the first digital electrical data stream to output a first filtered digital electrical data stream at an effective sampling rate that is less than the sampling rate and less than twice the symbol rate of the first and second analog electrical data streams, and greater than or equal to the symbol rate of the first and second analog electrical data streams;
• a second digital filter configured to digitally filter the second digital electrical data stream to output a second filtered digital electrical data stream at the effective sampling rate that is less than the sampling rate and less than twice the symbol rate of the first and second analog electrical data streams, and greater than or equal to the symbol rate of the first and second analog electrical data streams;
• and
• a downstream hardware unit that includes at least one component configured to process the first and second filtered digital electrical data streams at a rate that is substantially similar to the effective sampling rate to recover data in the optical signal received by the photonics module.