The present disclosure addresses methods for increasing and varying the range of control of wireless systems used in vehicles. The present invention enables varying ranges which allow a user, for example, to activate lights when an authorized vehicle user is in a close range, and to start the vehicle from a distance before the authorized vehicle user leaves the house. The described systems use variable frequency shift keying, variations in power transmissions, and user defined ranges that can be modified through Bluetooth communications.

Disclosed is a broadcast signal transmitting apparatus, a broadcast signal receiving apparatus, and a broadcast signal transceiving method in a broadcast signal transceiving apparatus. The broadcast signal transmitting method comprises the following steps: compressing the headers of data packets of an IP stream identified by IP address information, wherein the compressed data packets include a first packet, the header of which contains static field information, a second packet, the header of which contains dynamic field information, and a third packet, the header of which contains the compressed static field information and/or the compressed dynamic field information; signaling IP-PLP mapping information for mapping the IP stream and a component PLP for transmitting the IP stream, the IP stream compression information, and the header information of the first packet to L2 signaling information; and transmitting the header information of the second and third packets via the component PLP, and transmitting the L2 signaling information via a common PLP.

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.

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.

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.

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 resulting 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.

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.

An envelope signal time delay adjustment apparatus includes a negative group delay unit for converting an envelope signal input from a signal generator into an envelope signal having a group delay of a negative value whose frequency increases from a predetermined frequency band; an envelope-tracking modulator for power-amplifying and outputting the envelope signal output from the negative group delay unit; and a frequency limiting unit for limiting a bandwidth of the envelope-tracking modulator to be lower than an original bandwidth of the envelope-tracking modulator.

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.

The disclosure relates to an error-compensated direct digital modulation device, including: a direct digital radio frequency modulator (DDRM), configured to generate a radio frequency (RF) signal based on a modulation of a digital baseband signal; an error estimator configured to determine an error signal resulting from a deviation based on the generated RF signal and a representation of the digital baseband signal; and an error compensator configured to subtract the error signal from the RF signal to provide an error compensated RF signal.