Systems and methods may receive data from a data interface of a base platform, convert the data into an analog signal and modulate the analog signal onto a direct current (DC) power line coupled to a connector of the base platform. Additionally, the modulated analog signal may be received from a DC power line coupled to a connector of a tablet platform, wherein the modulated analog signal is converted to a digital signal and demodulated to recover the data. In one example, the data includes user input data associated with an input device including one or more of a mouse, a keyboard, a keypad or a touchpad.

In a signal generating device 2, first signal generation means 12 for generating a most significant bit signal stream MSB, second signal generation means 13 for generating a least significant bit signal stream LSB, a mask generation means 14 for defining a bit that allows error insertion and a bit that prohibits error insertion with different pieces of bit information, and generating a mask pattern of each of the most significant bit signal stream MSB and the least significant bit signal stream LSB, based on symbol transition information indicating a transition destination of four PAM4 symbols of a PAM4 signal; and error insertion means 15 for inserting an error, based on bit information of the mask pattern corresponding to each bit of the most significant bit signal stream and the least significant bit signal stream designated according to a symbol error rate.

Systems and methods are disclosed herein for modifying modulated signals for transmission. The system receives a modulated signal comprising a speech signal and a carrier wave and generates first and second spectral signals by converting the modulation signal and carrier wave from the time domain to the frequency domain respectively. The system then determines spectral bands for the first and second spectral signals. For each spectral band, the system calculates a weighted spectral band value based on a magnitude of the first spectral signal within the spectral band and generates a modified spectral signal by modifying the second spectral signal with the weighted spectral band value. The system then converts the modified spectral signal from the frequency domain to the time domain and transmits the converted modified spectral signal to a server.

System and method are described for implementing, in software and running on a general purpose processor, a communication protocol and using a communication system that supports one or more different communication protocols to transmit and receive data complaint with said communication protocol implemented in software.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for communicating signals using a multi-dimensional symbol constellation. In one example, a process for modulating a carrier signal includes the actions of mapping data to symbols of a multi-dimensional symbol constellation that includes at least three dimensions, each dimension of the constellation represented by a respective modulation signal. The dimensions of the constellation include first and second dimensions each of which are represented by respective in-phase modulation values and quadrature phase modulation values of a quadrature amplitude modulation (QAM) signal, and a third dimension represented by a transpositional modulation (TM) signal. The method further includes modulating a carrier signal with the TM signal and the QAM signal.

A candidate arbitrary-phase spread spectrum modulation technique that offers similar performance to spread continuous phase modulation (CPM) waveforms and additional capabilities for programming a chosen frequency domain spectra into the resulting spread spectrum signal. The proposed chaotic-FSK waveform is derived from high-order sequence-based spread spectrum signals, with multi-bit resolution chaos-based sequences defining incremental phase words, enabling real-time efficient generation of practically non-repeating waveforms. A result of the C-FSK formulation is a parameterized hybrid modulation capable of acting like a traditional sequence-based spread spectrum signal or a traditional frequency shift keying signal depending on chosen parameters. As such, adaptation in this modulation may be easily implemented as a time-varying evolution, increasing the security of the waveform while retaining many efficiently implementable receiver design characteristics of traditional PSK modulations.

Calibrating a Gaussian frequency-shift keying modulation index includes generating a training sequence of bits, shaping a pulse from the training sequence according to an initial modulation index, and converting the shaped signal to a transmission signal. The transmission signal is then either looped through a radio frequency core or processed by frequency deviation estimation hardware to determine a frequency deviation. The frequency deviation is converted to a new modulation index, and potentially a ratio between a target modulation index and a measured modulation index as a scaling factor. The process is then iteratively repeated until a threshold frequency deviation is achieved.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium for receiving, by a first device, a first signal from a second device, the first signal including a carrier signal modulated with a first modulation signal. Detecting a frequency of the carrier signal by performing a carrier extraction (CAREX) process on the first signal. Adding a second modulation signal to the carrier signal of the first signal to produce a combined signal, wherein the second modulation signal is a transpositional modulation (TM) signal and the first modulation signal is a non-TM signal. Transmitting the combined signal.

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for transmitting signals with a high data rate. In some implementations, an apparatus includes a first digital signal processor outputting first data at a first data rate. A second digital signal processor outputting second data at a second data rate. A filter circuitry receiving and up-sampling the first and second data. Additionally, the apparatus includes a combiner circuit that receives the first up-sampled data and the second up-sampled data, the combiner circuit combining the first and second up-sampled data to provide a multiplexed output, the multiplexed output having a third data rate that is greater than the first data rate or the second data rate.

Designs for a front end for suppressing adjacent channel interference (ACI) and adjacent leakage interference (ALI) in a full duplex cable modem (CM) for a Data Over Cable Service Interface Specification (DOCSIS) network are described. The CM includes an upstream (US) signal path receiving a digital US input signal and transmitting an analog-converted US signal in a US frequency range to a cable modem termination system (CMTS); a downstream (DS) signal path receiving an analog DS signal in a DS frequency range and converting the analog DS signal into a digital DS signal; and an echo cancellation (EC) circuit configured to subtract, from at least one of the analog DS signal and the digital DS signal, a correction signal generated from the digital US input signal or a correction signal generated from the analog-converted US signal to generate an echo-cancelled digital DS input signal without ACI and ALI.