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 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: 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: The present systems and methods may shape signals to meet emission mask requirements, current consumption requirements, and overshoot/undershoot requirements relating to the interaction that, for example, occurs when a near field communications (NFC) target comes within range of an NFC initiator, and the initiator generates and transmits an NFC waveform. In some implementations, a pair of bit patterns are defined whose differential output from an amplifier is a shaped pulse width modulated waveform. Varying individual bits of the bit patterns can vary the shaped pulse waveform with predictability. The pulse width modulated waveform may be filtered using a matching network that reduces higher order harmonics, thereby reducing out-of-band emissions.

Abstract: Systems and methods are disclosed that can shape signals to meet emission mask requirements, current consumption requirements, and overshoot/undershoot requirements relating to the interaction that, for example, occurs when a near field communications (NFC) target comes within range of an NFC initiator, and the initiator generates and transmits an NFC waveform. In some implementations, a pair of bit patterns are defined whose differential output from an amplifier is a shaped pulse width modulated waveform. Varying individual bits of the bit patterns can vary the shaped pulse waveform with predictability. The pulse width modulated waveform may be filtered using a matching network that reduces higher order harmonics, thereby reducing out-of-band emissions.

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: 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 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: An apparatus for coding a communication signal is provided. The apparatus includes an encoder configured to encode the communication signal, to increase the length of the communication signal, and a repetition coder configured to repetitively code part of the encoded communication signal, to utilize at least some of the increased length of the communication signal. The apparatus further includes an interleaver configured to interleave the repetitively coded communication signal. A method is also provided for coding a communication signal.

Abstract: A method of switching between Coherent and Non-Coherent demodulation based on computed metrics, in cases where stereo FM broadcasting stations do not adhere to RDS broadcast specifications. Re-utilizes existing hardware to demodulate RDS data in mono. The residual frequency offset is resolved using a Non Coherent demodulator and a time tracking algorithm. RDS data relies on the 57 kHz sub-carrier that is generated using 19 kHz pilot tone. In Mono broadcasting pilot tone is not present. A local 57 kHz free running signal is generated, and this is then used to demodulate the RDS data in Non-Coherent mode.

Abstract: An apparatus for coding a communication signal is provided. The apparatus includes an encoder configured to encode the communication signal, to increase the length of the communication signal, and a repetition coder configured to repetitively code part of the encoded communication signal, to utilize at least some of the increased length of the communication signal. The apparatus further includes an interleaver configured to interleave the repetitively coded communication signal. A method is also provided for coding a communication signal.