Optical communication interface utilizing N-dimensional double square quadrature amplitude modulation
View Patent ↗The present invention is directed to data communication system and methods. More specifically, various embodiments of the present invention provide a communication interface that is configured to transfer data at high bandwidth using nDSQ format(s) over optical communication networks. In certain embodiments, the communication interface is used by various devices, such as spine switches and leaf switches, within a spine-leaf network architecture, which allows large amount of data to be shared among servers.
1. A communication device configured to generate n-dimensional double square quadrature amplitude modulation (nDSQ) coded signals for pulse amplitude modulation with m levels (PAMm), the device comprising:
a communication interface for receiving incoming data;
a clock data recovery circuit configured to process the incoming data;
an encoder configured to encode the incoming data into coded symbols, each coded symbols comprising most significant bits (MSBs) and least significant bits (LSBs);
a symbol mapper that maps the coded symbols into the n-dimensional DSQ constellation, wherein:
the MSBs comprising (2*n) bits are mapped to PAM (m/2) symbols;
the LSBs comprising (n−1) bits are mapped to PAM2 symbols with a 1-bit parity;
the PAM (m/2) symbols and the PAM2 symbols are added to generate the nDSQ coded signals.
2. The device of claim 1 wherein the coded data comprises data in BCH format or and/or RS format.
3. The device of claim 1 wherein the nDSQ coded signals used for PAMm modulation.
4. The device of claim 1 wherein n is an integer greater or equal to 2.
5. The device of claim 1 wherein m is 8, 12, 16, or 32.
6. A method for generating n-dimensional double square quadrature amplitude modulation (nDSQ) coded signals for pulse amplitude modulation with m levels (PAMm), the method comprising:
receiving, using a communication interface, an incoming data stream;
process, using a clock data recovery circuit, the incoming data stream;
encoding, using an encoder, the incoming data into coded symbols, each coded symbols comprising most significant bits (MSBs) and least significant bits (LSBs);
mapping, using a symbol mapper, the MSBs comprising (2*n) bits to PAM (m/2) symbols;
mapping, using the symbol mapper, the LSBs comprising (n−1) bits to PAM2 symbols;
appending a 1-bit parity to the PAM2 symbols; and
combining the PAM (m/2) symbols and the PAM2 symbols to generate the nDSQ coded signals.
7. The method of claim 6 further comprising adding the PAM (m/2) symbols and the PAM2 symbols.
8. The method of claim 6 further comprising encoding the LSBs with BCH or RS code.
9. The method of claim 6 further comprising mapping the MSBs comprising (2*n) bits to PAM (m/2) symbols using a Gray mapping process.
10. The method of claim 6 further comprising modulating the nDSQ coded signals.