Abstract: Systems and methods are directed to phase modulation of polar coordinates in a transmitter of wireless signals, to achieve high transmit power levels while meeting spectral mask and EVM requirements. An input signal is mapped to a sequence of modulation frequency (e.g., O-QPSK to MSK) to generate a mapped signal. A digital frequency shaping filter is applied to the mapped signal to generate a shaped signal. An adaptive rounding algorithm is applied to the shaped signal to generate a reduced bit-width signal. A digital frequency synthesizer is applied to the reduced bit-width signal to generate an analog waveform for transmission.

Abstract: Methods and systems for hardware-efficient carrier sensing are disclosed. The method may include receiving a received signal during a detection window, generating a phase-discriminated waveform based on the received signal, determining a plurality of absolute values respectively based on a plurality of correlations of the phase-discriminated waveform, and generating a detection metric based on a peak value of the plurality of absolute values.

Abstract: Systems and methods are directed to phase modulation of polar coordinates in a transmitter of wireless signals, to achieve high transmit power levels while meeting spectral mask and EVM requirements. An input signal is mapped to a sequence of modulation frequency (e.g., O-QPSK to MSK) to generate a mapped signal. A digital frequency shaping filter is applied to the mapped signal to generate a shaped signal. An adaptive rounding algorithm is applied to the shaped signal to generate a reduced bit-width signal. A digital frequency synthesizer is applied to the reduced bit-width signal to generate an analog waveform for transmission.

Abstract: In an embodiment, a receiver detects a timing error between a transmitter clock at a transmitter and a receiver clock at a receiver associated with an exchange of CPM signals. The receiver phase aligns input samples of a candidate received signal over a time window based on a rotating signal corresponding to a phase progression of the candidate received signal. The receiver generates first and second partial sums of the phase-aligned input samples that are accumulations of phase-aligned input samples corresponding to modulation symbols that contribute positive and negative phases, respectively, to the phase progression. The receiver determines a phase difference between the first and second partial sums, and generates a timing-error metric that is indicative of a timing error between the transmitter clock and the receiver clock based at least in part upon the determined phase difference.

Abstract: In one aspect, a method for estimating residual carrier frequency offset (CFO) in a phase-modulated wireless signal having pseudo noise (PN) spreading is provided. The method includes receiving, at a digital transceiver, a plurality of PN spread blocks of in-phase and quadrature (I/Q) samples of the phase-modulated wireless signal and performing sample-level de-rotation, symbol-level de-spreading, and sign alignment. The method also includes estimating a phase difference and determining an estimated residual CFO based on the phase difference.

Abstract: A method for setting an initial gain and an initial offset for an automatic gain and offset controller (AGOC) is described. The method includes determining a gain level at which a signal does not under-saturate or over-saturate an input to an analog-to-digital converter (ADC) by performing a binary search over a fixed set of gain levels while an offset is fixed. The method also includes determining an offset correction to bring an unmodulated carrier level at an output of the ADC to a target level. The method may also include updating the gain and the offset in response to changes in a signal level.

Abstract: A method for inductively-coupled communications is described. The method includes receiving a signal. The method also includes analyzing the signal to estimate a symbol timing error. Estimating the symbol timing error may include comparing a location of a pause, a low-to-high or a high-to-low transition in the received signal with an ideal location of a pause or a transition. The method further includes adjusting symbol timing to correct for the symbol timing error.

Abstract: A method for setting an initial gain and an initial offset for an automatic gain and offset controller (AGOC) is described. The method includes determining a gain level at which a signal does not under-saturate or over-saturate an input to an analog-to-digital converter (ADC) by performing a binary search over a fixed set of gain levels while an offset is fixed. The method also includes determining an offset correction to bring an unmodulated carrier level at an output of the ADC to a target level. The method may also include updating the gain and the offset in response to changes in a signal level.

Abstract: A method for inductively-coupled communications is described. The method includes receiving a signal. The method also includes analyzing the signal to estimate a symbol timing error. Estimating the symbol timing error may include comparing a location of a pause, a low-to-high or a high-to-low transition in the received signal with an ideal location of a pause or a transition. The method further includes adjusting symbol timing to correct for the symbol timing error.