In one embodiment, a dual-mode power amplifier that can operate in different modes includes: a first pair of metal oxide semiconductor field effect transistors (MOSFETs) to receive and pass a constant envelope signal; a second pair of MOSFETs to receive and pass a variable envelope signal, where first terminals of the first pair of MOSFETs are coupled to first terminals of the second pair of MOSFETs, and second terminals of the first pair of MOSFETs are coupled to. second terminals of the second pair of MOSFETs; and a shared MOSFET stack coupled to the first pair of MOSFETs and the second pair of MOSFETs.

In one embodiment, a dual-mode power amplifier that can operate in different modes includes: a first pair of metal oxide semiconductor field effect transistors (MOSFETs) to receive and pass a constant envelope signal; a second pair of MOSFETs to receive and pass a variable envelope signal, where first terminals of the first pair of MOSFETs are coupled to first terminals of the second pair of MOSFETs, and second terminals of the first pair of MOSFETs are coupled to. second terminals of the second pair of MOSFETs; and a shared MOSFET stack coupled to the first pair of MOSFETs and the second pair of MOSFETs.

In one embodiment, a dual-mode power amplifier that can operate in different modes includes: a first pair of metal oxide semiconductor field effect transistors (MOSFETs) to receive and pass a constant envelope signal; a second pair of MOSFETs to receive and pass a variable envelope signal, where first terminals of the first pair of MOSFETs are coupled to first terminals of the second pair of MOSFETs, and second terminals of the first pair of MOSFETs are coupled to. second terminals of the second pair of MOSFETs; and a shared MOSFET stack coupled to the first pair of MOSFETs and the second pair of MOSFETs.

Embodiments may provide a way of communicating via an electromagnetic radiator, or light source, that can be amplitude modulated such as light emitting diode (LED) lighting and receivers or detectors that can determine data from light received from the amplitude modulated electromagnetic radiator. Some embodiments may provide a method of transmitting/encoding data via modulated LED lighting and other embodiments may provide receiving/decoding data from the modulated LED lighting by means of a device with a low sampling frequency such as a relatively inexpensive camera (as might be found in a smart phone). Some embodiments are intended for indoor navigation via photogrammetry (i.e., image processing) using self-identifying LED light anchors. In many embodiments, the data signal may be communicated via the light source at amplitude modulating frequencies such that the resulting flicker is not perceivable to the human eye.

A signal folding device receives an input signal, and performs frequency modulation on a plurality of first analog signals based on the input signal to obtain a plurality of modulated first analog signals, where a frequency difference between two adjacent first analog signals in the plurality of modulated first analog signals is the same. The signal folding device may filter the plurality of modulated first analog signals based on a specified bandwidth to obtain a second analog signal, and demodulate the second analog signal to obtain an output signal. The output signal is a folded signal of the input signal within a target amplitude, and the second analog signal is an analog signal within the bandwidth.

A method, system, and apparatus for applying dithering to waveforms in a transmitter such as a Bluetooth transmitter. A current waveform corresponding to a current bit of a bitstream is received where the current waveform has a nominal frequency deviation defined by a value of the current bit. Based on the determination that the current waveform and an immediately previous bit of the bitstream are associated with different bit values, a first dithered signal is output which is defined by a first frequency offset pseudorandomly selected from a first set of frequency offsets. A subsequent waveform to the current waveform is received corresponding to a subsequent bit of the bitstream. Based on the subsequent bit and the current bit being associated with bits of the same value, a second dithered signal is output which is defined by a second frequency offset pseudorandomly selected from a second set of frequency offsets.

A method, system, and apparatus for applying dithering to waveforms in a transmitter such as a Bluetooth transmitter. A current waveform corresponding to a current bit of a bitstream is received where the current waveform has a nominal frequency deviation defined by a value of the current bit. Based on the determination that the current waveform and an immediately previous bit of the bitstream are associated with different bit values, a first dithered signal is output which is defined by a first frequency offset pseudorandomly selected from a first set of frequency offsets. A subsequent waveform to the current waveform is received corresponding to a subsequent bit of the bitstream. Based on the subsequent bit and the current bit being associated with bits of the same value, a second dithered signal is output which is defined by a second frequency offset pseudorandomly selected from a second set of frequency offsets.

A redundant star network is disclosed. The network includes a peripheral device (PD), a control hub, and a backup hub. The control hub and backup hub each have a wireless long range transceiver, hardware processors, and hardware memory. The PD includes a wireless long range transceiver and a microcontroller. The control hub and backup hub hardware memories store system operation information. The system operation information includes instructions for controlling the PD. The PD microcontroller includes test firmware and update firmware. The test firmware instructs the PD to test the control hub and to listen for a test response signal indicating the control hub is operational. The PD update firmware instructs the PD to switch control of the PD to the backup hub when the test response signal is not received within an expected response timeframe after the test signal is sent.

A method of transmitting a signal using a plurality of modulation and coding schemes by a transmitter in a wireless communication system is provided. The method includes when a position of an active tone hits a position of a pilot tone of an adjacent cell, the active tone corresponding to a tone boosted through an application of a hybrid Frequency Shift Keying (FSK) and Quadrature Amplitude Modulation (QAM) Modulation (FQAM) scheme among tones included in an FQAM symbol based on the FQAM scheme in which a QAM scheme and a FSK scheme are combined, detecting two or more tones, which do not hit the position of the pilot tone among the tones included in the FQAM symbol, and transmitting signals by using the detected two or more tones.

A transmitter for use in a communication system uses a orthogonal modulation method, and the transmitter includes: an orthogonal sequence prescriber that prescribes association between orthogonal signals and information words determined on the basis of sizes of differences between information words of a plurality of mutually different information words and a probability of occurrence of decision errors between orthogonal signals of a plurality of mutually orthogonal signals; and a symbol mapper that, upon input of any of the information words, generates modulation symbols based on the orthogonal signals associated with the input information word according to the associations prescribed by the orthogonal sequence prescriber.