A carrier-phase recovery method includes: (i) applying a first carrier-phase recovery algorithm to complex-valued symbols of a signal received by a product detector, yielding coarse phase-estimates, the signal being modulated per an M-QAM scheme; (ii) modelling the coarse phase-estimates as a weighted sum of M probability-density functions of an M-component mixture model; (iii) optimizing the M probability-density functions with an expectation-maximization algorithm to yield M optimized probability-density functions; (iv) mapping, based on the M optimized probability-density functions, the coarse phase-estimates to one of M symbols corresponding to the QAM scheme, each coarse phase-estimate mapped to a same symbol belonging to a same one of M clusters; (v) applying a second carrier-phase recovery algorithm to each of the M clusters to generate refined phase-estimates each corresponding to a respective coarse phase-estimate; and (vi) mapping, based on the M optimized probability-density functions, each refined phase-estimate to one of the M symbols.

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.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for modulating and demodulating transpositional modulated (TM) signals. One aspect features a method of modulating a carrier signal that include the actions of generating a TM signal by generating a sinusoidal signal, and modulating the sinusoidal signal based on a data signal to provide the TM signal. Inserting the TM signal into a carrier signal to provide a TM modulated carrier signal. Modulating the TM modulated carrier signal with a non-TM signal to provide a combined signal. Transmitting the combined signal.

A system and method for MIB estimation including generating a signal model for rank=2, based on the reference signals of a received wireless signal; converting the signal model to a four-parameter representation; determining, for values of parameters derived from the four-parameter representation, whether mutual information per bit (MIB) values depend on a single parameter or on a plurality of parameters; if the MIB values depend on the single parameter, calculating MIB values based on the single parameter; and if the MIB values depend on the plurality of parameters, calculating MIB values based on the plurality of parameters. Calculating MIB values based on the single parameter, determining, whether MIB values depend on a single parameter or on a plurality of parameters and, calculating MIB values based on the plurality of parameters, are performed using a machine learning algorithm.

In one embodiment, a method analyzes a size of a grant included in an upstream transmission from the device using a radio frequency over an optical network. When the size of the grant is less than a threshold, scheduling the upstream transmission on a first type of channel. The first type of channel includes characteristics of transmission such that an optical transmitter of an optical networking unit that receives the upstream transmission from the device will turn on when transmitting the upstream transmission via the optical network. When the size of the grant is greater than the threshold, scheduling the upstream transmission on a second type of channel. The size of the grant is such that the optical transmitter that receives the upstream transmission from the device is predicted to turn on when transmitting the upstream transmission via the optical network.

The continuous demand for capacity and the limited available spectrum in wireless and wired communication has led to reliance on advanced modulation techniques to dramatically increase the number of bits per hertz per second. This demand in capacity and using the higher order constellations shorten the link range, and as a result, system gain becomes an important characteristic. The modulation techniques described here improve the system gain by, e.g., as much as 2.5 dB in high order modulations such as 4096-QAM. The modulation techniques include reducing the peak to average ratio and adding shaping gain. These techniques dramatically improve the system capacity, system gain, power consumption and system cost.

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.

The continuous demand for capacity and the limited available spectrum in wireless and wired communication has led to reliance on advanced modulation techniques to dramatically increase the number of bits per hertz per second. This demand in capacity and using the higher order constellations shorten the link range, and as a result, system gain becomes an important characteristic. The modulation techniques described here improve the system gain by, e.g., as much as 2.5 dB in high order modulations such as 4096-QAM. The modulation techniques include reducing the peak to average ratio and adding shaping gain. These techniques dramatically improve the system capacity, system gain, power consumption and system cost.

A system and method for MIB estimation including generating a signal model for rank=2, based on the reference signals of a received wireless signal; converting the signal model to a four-parameter representation; determining, for values of parameters derived from the four-parameter representation, whether mutual information per bit (MIB) values depend on a single parameter or on a plurality of parameters; if the MIB values depend on the single parameter, calculating MIB values based on the single parameter; and if the MIB values depend on the plurality of parameters, calculating MIB values based on the plurality of parameters. Calculating MIB values based on the single parameter, determining, whether MIB values depend on a single parameter or on a plurality of parameters and, calculating MIB values based on the plurality of parameters, are performed using a machine learning algorithm.

Provided are a data transmission method and apparatus, a communication node, and a storage medium. The method includes the following: Data is modulated in a time domain according to a set modulation manner to obtain modulated data, where the set modulation manner is associated with a time domain position of a modulation symbol in the modulated data; and the modulated data is transmitted.