A communication system that uses keyed modulation to encode fixed frequency communications on a variable frequency power transmission signal in which a single communication bit is represented by a plurality of modulations. To provide a fixed communication rate, the number of modulations associated with each bit is dynamic varying as a function of the ratio of the communication frequency to the carrier signal frequency. In one embodiment, the present invention provides dynamic phase-shift-keyed modulation in which communications are generated by toggling a load at a rate that is a fraction of the power transfer frequency. In another embodiment, the present invention provides communication by toggling a load in the communication transmitter at a rate that is phase locked and at a harmonic of the power transfer frequency. In yet another embodiment, the present invention provides frequency-shift-keyed modulation, including, for example, modulation at one of two different frequencies.

A ternary pulse width modulation (PWM) method and apparatus. In one embodiment, the start of the pulse sequence in the current frame is referenced to the end of the pulse sequence in a previous, reference frame, rather than to the frame boundary at the start of the current frame, thereby allowing the compensation portion of the pulse sequence to overlap into the preceding or following frame, thus achieving a higher modulation index without dropping the compensation pulses. Although in most instantiations, the reference frame will be the frame immediately preceding in time the current frame, in other instances, the reference frame may be any frame preceding the current frame that falls within the constraints of the timing facility.

A ternary pulse width modulation (PWM) method and apparatus. In one embodiment, the start of the pulse sequence in the current frame is referenced to the end of the pulse sequence in a previous, reference frame, rather than to the frame boundary at the start of the current frame, thereby allowing the compensation portion of the pulse sequence to overlap into the preceding or following frame, thus achieving a higher modulation index without dropping the compensation pulses. Although in most instantiations, the reference frame will be the frame immediately preceding in time the current frame, in other instances, the reference frame may be any frame preceding the current frame that falls within the constraints of the timing facility.

Provided is a pulse area modulation apparatus including: a register configured to receive and store PCM data having n+m bits per a sample; an amplitude shaping unit configured to shape an amplitude of an output pulse to correspond to the n bits; a duration forming unit configured to form duration of the output pulse to correspond to the m bits; and a charge accumulation means providing an output pulse, wherein a pulse area of the output pulse defined by the amplitude and the duration is modulated according to the sample.

A wireless communications device may include a wireless receiver, and an adaptive demodulator coupled to the wireless receiver. The adaptive demodulator is configured to apply first and second bandpass filters to amplitude information of a received signal at first and second frequency bands, respectively, and classify the received signal as one of a PSK modulation type, a second PSK modulation type, and a third FSK modulation type based upon whether a tone exists in the amplitude information of the received signal in one or more of the first and second frequency bands. The adaptive demodulator is configured to adjust a demodulating parameter based upon a classified modulation type of the received signal.

A pipelined decimation in frequency FFT butterfly method, and an apparatus to perform this method comprising: a data memory with at least one read port and one write port; an add/subtract unit receiving data from the memory; a multiply/accumulate unit receiving data from the add/subtract unit; a source of coefficients, from logic gates or a coefficient memory, to supply FFT twiddle factors to the multiply/accumulate unit; a shifter receiving data from at least one of the add/subtract unit and the multiply/accumulate unit, the shifter supplying data to the write port of the data memory; wherein the apparatus performs these calculations in four cycles of the add/subtract unit and in four cycles of the multiply/accumulate unit, using complex arithmetic.

Multi-user superposition transmissions (MUSTs) on non-aligned resources are described. A base station may schedule a transmission to an enhancement layer user equipment (UE) and a base layer UE. The transmission may include a base layer that spans a base layer resource set and an enhancement layer that spans an enhancement layer resource set, where the resource sets may be aligned or un-aligned. The base station may use a combined constellation to map symbols to the base layer resource set for communication with the enhancement layer and base layer UEs over overlapping portions of the resource sets, and an extended constellation to map symbols to an extended set of resources for which the enhancement layer resource set is exclusive of the base layer resource set. The extended constellation may be based on an extended modulation order determined based on a base modulation order and an enhancement modulation order.

Multi-user superposition transmissions (MUSTs) on non-aligned resources are described. A base station may schedule a transmission to an enhancement layer user equipment (UE) and a base layer UE. The transmission may include a base layer that spans a base layer resource set and an enhancement layer that spans an enhancement layer resource set, where the resource sets may be aligned or un-aligned. The base station may use a combined constellation to map symbols to the base layer resource set for communication with the enhancement layer and base layer UEs over overlapping portions of the resource sets, and an extended constellation to map symbols to an extended set of resources for which the enhancement layer resource set is exclusive of the base layer resource set. The extended constellation may be based on an extended modulation order determined based on a base modulation order and an enhancement modulation order.

A ternary pulse width modulation (PWM) method and apparatus. In one embodiment, the start of the pulse sequence in the current frame is referenced to the end of the pulse sequence in a previous, reference frame, rather than to the frame boundary at the start of the current frame, thereby allowing the compensation portion of the pulse sequence to overlap into the preceding or following frame, thus achieving a higher modulation index without dropping the compensation pulses. Although in most instantiations, the reference frame will be the frame immediately preceding in time the current frame, in other instances, the reference frame may be any frame preceding the current frame that falls within the constraints of the timing facility.

A ternary pulse width modulation (PWM) method and apparatus. In one embodiment, the start of the pulse sequence in the current frame is referenced to the end of the pulse sequence in a previous, reference frame, rather than to the frame boundary at the start of the current frame, thereby allowing the compensation portion of the pulse sequence to overlap into the preceding or following frame, thus achieving a higher modulation index without dropping the compensation pulses. Although in most instantiations, the reference frame will be the frame immediately preceding in time the current frame, in other instances, the reference frame may be any frame preceding the current frame that falls within the constraints of the timing facility.