Methods, systems, and apparatus for receiving an input signal, where the input signal includes a carrier signal modulated with a first modulation signal and a second modulation signal, and where the second modulation signal is a TM signal. Demodulating the first modulation signal from the input signal. Modulating an un-modulated carrier signal with the first modulation signal to generate a third signal, where the third signal includes the carrier signal modulated by the first modulation signal. And, removing the first modulation signal from the input signal by subtracting the third signal from the input signal to extract the TM signal from the input signal.

A method of encoding a plurality of data signals is disclosed. The method includes selecting a set of M ultrasonic frequencies, wherein each of the M ultrasonic frequencies differs from an adjacent frequency by at least a first frequency spacing, and wherein M is a positive integer. An encoder receives the plurality of data signals. Each of the plurality of data signals is encoded by a respective set of Q of the M ultrasonic frequencies, wherein Q is a positive integer less than M. A minimum frequency separation between any pair of the Q ultrasonic frequencies of any respective set is greater than the first frequency spacing.

An alternative approach to coping with the ever increasing demand for faster communications hardware is to design modems that are capable of operating its speeds at a higher data rate than a speed required for a single port of the standard communication rate for that modem. Basically, by utilizing a resource manager, that directs the data in and out of the various portions of the modem in an orderly manner, keeping track of which of the ports is being operated at any given point in time, a standard single port modem can be reconfigured, for example, at an over clocked rate, to manipulate the data input and output of a modem.

A method of transmitting and receiving a signal and an apparatus for transmitting and receiving a signal are provided. The method includes receiving the signal of a first frequency band, obtaining Layer-1 (L1) information from a preamble of a first time-frequency slicing (TFS) signal frame of the received signal, the layer-1 information including a radio frequency (RF) channel identifier of the first TFS signal frame including a physical layer pipe (PLP) in a super frame of TFS structure and including an identifier of a starting radio RF channel that can receive the PLP in the first TFS signal frame, parsing the first TFS signal frame using the L1 information and obtaining a PLP of the first TFS signal frame, and converting the PLP to a service stream.

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.

Communication systems and methods in accordance with various embodiments of the invention utilize modulation on zeros. Carrier frequency offsets (CFO) can result in an unknown rotation of all zeros of a received signal's z-transform. Therefore, a binary MOCZ scheme (BMOCZ) can be utilized in which the modulated binary data is encoded using a cycling register code (e.g. CPC or ACPC), enabling receivers to determine cyclic shifts in the BMOCZ symbol remitting from a CFO. Receivers in accordance with several embodiments of the invention include decoders capable of decoding information bits from received discrete-time baseband signals by: estimating a timing offset for the received signal; determining a plurality of zeros of a z-transform of the received symbol; identifying zeros from the plurality of zeros that encode received bits by correcting fractional rotations resulting from the CFO; and decoding information bits based upon the received bits using a cycling register code.

Methods, systems, and apparatus for receiving an input signal, where the input signal includes a carrier signal modulated with a first modulation signal and a second modulation signal, and where the second modulation signal is a TM signal. Demodulating the first modulation signal from the input signal. Modulating an un-modulated carrier signal with the first modulation signal to generate a third signal, where the third signal includes the carrier signal modulated by the first modulation signal. And, removing the first modulation signal from the input signal by subtracting the third signal from the input signal to extract the TM signal from the input signal.

Methods, systems, and apparatus for detecting a center frequency of an input signal, the input signal including a carrier signal modulated with a modulation signal. Detecting a frequency of a second signal. Determining a difference signal between the center frequency of the input signal and the frequency of the second signal. Modifying the frequency of the second signal based on the difference signal to provide the carrier signal. And, outputting the carrier signal.

A central access network unit comprising a processor configured to assign a plurality of upstream training blocks from an upstream OFDM symbol to a plurality of downstream network units, wherein the OFDM symbol comprises a plurality of pilot subcarriers equally spaced across an upstream RF spectrum in a pre-determined time interval, and wherein each upstream training block comprises a different subset of the pilot subcarriers that are non-consecutive and situated across the upstream RF spectrum, and generate one or more messages comprising assignments of the upstream training blocks, and a transmitter coupled to the processor and configured to transmit the messages to the plurality of downstream network units via a network, wherein the messages instruct at least one of the plurality of downstream network units to transmit a modulated pre-determined sequence at the pilot subcarriers corresponding to the upstream training block assigned to the downstream network unit.

A wireless transmission system includes: a communication unit for transmission; and a communication unit for reception. The communication units for transmission and reception are housed in a housing of the same electronic apparatus, or the communication unit for transmission is housed in a housing of first electronic apparatus and the communication unit for reception is housed in a housing of second electronic apparatus and a wireless signal transmission path enabling wireless information transmission between the communication units is formed between the communication units when the first and the second electronic apparatus are disposed at given positions to be integrated with each other. The communication unit for transmission includes a first carrier signal generating unit and a first frequency converter, and the communication unit for reception includes a second carrier signal generating unit, and a second frequency converter.