Abstract: A method for dynamic sizing of a blocker margin by a receiver automatic gain control (AGC) is described. The method includes measuring a wanted signal level and a blocker signal level. The method also includes adjusting a linear target for the wanted signal level at the output of an analog-to-digital converter (ADC) of the receiver based on the blocker signal level. The linear target is adjusted to optimize a wanted signal signal-to-noise ratio (SNR) and the blocker margin. The method further includes adjusting a receiver front-end gain based on the adjusted linear target.

Abstract: Systems and methods are directed to low cost and low power carrier frequency offset (CFO) estimation in a receiver. In-phase (I) and quadrature (Q) samples of a wireless signal are received by the receiver and a first phase and a second phase are extracted from the outputs of a first autocorrelator with a first time-lag and a second autocorrelator with a second time-lag. The extracted first and second phases are combined to generate an estimated CFO of high accuracy and wide estimation range.

Abstract: Systems and methods pertain to operating a receiver of wireless signals such as Bluetooth or Bluetooth Low Energy (BLE) signals. A correlator is provided to correlate a wireless signal received by the receiver with a device identifier corresponding to a wanted device from which the receiver wants to receive wireless signals, to generate a correlator output. An adaptive acquisition threshold generator generates an adaptive acquisition threshold based on a signal strength of the wireless signal, and a comparator is used to determine if the wireless signal is a wanted signal intended for the receiver, based on a comparison of the correlator output with the adaptive acquisition threshold.

Abstract: A method for dynamic sizing of a blocker margin by a receiver automatic gain control (AGC) is described. The method includes measuring a wanted signal level and a blocker signal level. The method also includes adjusting a linear target for the wanted signal level at the output of an analog-to-digital converter (ADC) of the receiver based on the blocker signal level. The linear target is adjusted to optimize a wanted signal signal-to-noise ratio (SNR) and the blocker margin. The method further includes adjusting a receiver front-end gain based on the adjusted linear target.

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 performed by a wireless device includes receiving a first signal that contains one or more modulated symbols and determining a signal strength of the first signal. The method also includes adjusting a remembrance factor based on the signal strength of the first signal and demodulating the one or more modulated symbols based on the first signal and based on a number of previously demodulated symbols. The number of previously demodulated symbols utilized in the demodulation is based on the remembrance factor.

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 includes demodulating a load modulated signal at an initiator device based at least partially on a phase adjusted comparison value corresponding to the load modulated signal.

Abstract: Aspects disclosed herein relate to improving acquisition for NFC load modulation. In one example, a communications device is equipped to monitor at least a complex component of load modulation of a carrier signal, detect, using a NFC technology type specific peak detection scheme, a peak associated with at least the complex component, and determine a presence of a packet beginning pattern based on the detected peak. In an aspect, the packet beginning pattern may be associated with a reception of a packet from a target NFC device.

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 improving communication sensitivity by a wireless communication device is described. The method includes obtaining a string of bits. The method also includes mapping each bit in the string of bits to a pre-allocated bit pattern to create a series of concatenated pre-allocated bit patterns. The method further includes generating a modulated signal based on the series. The method additionally includes transmitting the modulated signal.

Abstract: Methods, systems, and devices are described for an adaptive demodulator that supports multiple modes. An FM signal may be received at a demodulator and parameters corresponding to the FM signal may be identified. Connections between multiple modules within the demodulator may be configured, based at least in part on the parameters, to select one of multiple demodulation modes supported by the demodulator to demodulate the FM signal. The modes may include a phase differencing mode, a phase-locked loop (PLL) mode, a frequency-compressive feedback (FCF) mode, and/or a quadrature detector mode. The parameters may include one or both of a signal strength of the FM signal and a maximum frequency deviation of the FM signal. Based on the parameters, one or more signals may be generated to configure the connections within the demodulator. A switch from one mode to another may occur when one of the parameters breaches a threshold value.

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: Aspects disclosed herein relate to improving acquisition for NFC load modulation. In one example, a communications device is equipped to monitor at least a complex component of load modulation of a carrier signal, detect, using a NFC technology type specific peak detection scheme, a peak associated with at least the complex component, and determine a presence of a packet beginning pattern based on the detected peak. In an aspect, the packet beginning pattern may be associated with a reception of a packet from a target NFC device.

Abstract: Systems and methods are disclosed for compensating I-Q imbalance in a wireless receiver. The receiver may employ a quadrature downconverter configured to receive an RF signal input and output an in-phase component and a quadrature component at an IF, an IF rotation block configured to downconvert the in-phase and quadrature components to baseband and an I-Q correction block configured to compensate for an I-Q imbalance in the received signal, wherein the I-Q correction block is positioned downstream from the IF rotation block in the signal path. Performing the I-Q correction after conversion to baseband may allow the compensation calculations to operate at a reduced digital rate. Similarly, digitally adjusting the gain of the signal prior to I-Q compensation may reduce the number of bits that are manipulated during the compensation process. These features may represent significant efficiencies as compared to I-Q corrections performed at IF.

Abstract: Methods, systems, and devices are described for an adaptive demodulator that supports multiple modes. An FM signal may be received at a demodulator and parameters corresponding to the FM signal may be identified. Connections between multiple modules within the demodulator may be configured, based at least in part on the parameters, to select one of multiple demodulation modes supported by the demodulator to demodulate the FM signal. The modes may include a phase differencing mode, a phase-locked loop (PLL) mode, a frequency-compressive feedback (FCF) mode, and/or a quadrature detector mode. The parameters may include one or both of a signal strength of the FM signal and a maximum frequency deviation of the FM signal. Based on the parameters, one or more signals may be generated to configure the connections within the demodulator. A switch from one mode to another may occur when one of the parameters breaches a threshold value.

Abstract: Methods, systems, and devices are described for wireless communications in a frequency modulation (FM) receiver with a frequency deviation-dependent adaptive channel filter. A maximum frequency deviation of an FM broadcast signal may be estimated. One or more coefficients of a channel filter may be adapted based at least in part on the maximum frequency deviation. The coefficient adaptation may include identifying a set of coefficients corresponding to the maximum frequency deviation and applying the set of coefficients to the channel filter. The set of coefficients may be identified by selecting one of multiple sets of coefficients stored in memory. In some instances, a signal quality metric (e.g., signal-to-noise ratio (SNR)) may be identified and may be used to modify a value of one or more of the set of coefficients applied to the channel filter.

Abstract: A method for improving communication sensitivity by a wireless communication device is described. The method includes obtaining a string of bits. The method also includes mapping each bit in the string of bits to a pre-allocated bit pattern to create a series of concatenated pre-allocated bit patterns. The method further includes generating a modulated signal based on the series. The method additionally includes transmitting the modulated signal.

Abstract: In a wireless near field communication (NFC) system, a target, such as a smart card, can communicate with an initiator, such as a card reader, by load modulating a radio frequency (RF) signal generated by the initiator. When two or more targets load modulate the RF signal generated, “collisions” can occur with the load modulation. Apparatus and methods detect the presence or absence of collisions in a lower layer or physical layer and report the presence of detected collisions to an upper layer for further handling.

Abstract: Systems and methods to detect the occurrence of erroneous demodulated bits for decision feedback demodulation are disclosed. In one implementation, an apparatus for detecting demodulation bit errors of a plurality of modulated bits includes a memory component configured to store a first threshold and a second threshold. The apparatus further includes a processor coupled to the memory component, the processor configured to retrieve the first threshold and second threshold from the memory component and to determine a demodulation metric value for each of the plurality of modulated bits, the processor further configured to count the number of demodulation metric values that cross the first threshold and compare the second threshold to the number of demodulation metric values that cross the first threshold.