Methods, systems, and devices for improving uniformity between levels of a multi-level signal are described. Techniques are provided herein to unify vertical alignment between data transmitted using multi-level signaling. Such multi-level signaling may be configured to capture transmitted data during a single clock cycle of a memory controller. An example of multi-level signaling scheme may be pulse amplitude modulation (PAM). Each unique symbol of the multi-level signal may be configured to represent a plurality of bits of data.

A mobile computing device including a modal antenna is disclosed. The mobile computing device may include a radio frequency circuit and a modal antenna mechanically coupled to a portion of the mobile computing at a location that is remote from the radio frequency circuit. The modal antenna may include a driven element and a parasitic element positioned proximate to the driven element. The modal antenna may be operable in a plurality of different modes. Each mode may be associated with a different radiation pattern. The mobile computing device may include a transmission line coupling the radio frequency circuit to the modal antenna. The radio frequency circuit may be configured to transmit an RF signal over the transmission line to the modal antenna and configured to communicate a control signal to adjust the mode of the modal antenna over the transmission line.

A method for receiving a modulated signal, includes the steps of receiving a signal modulated by a pulse position modulation (PPM) or a pulse width modulation (PWM) or a pulse amplitude modulation (PAM) or an on-off keying (OOK) amplitude modulation, corresponding to the transmission of a sequence of one or more consecutive digital symbols, squaring the received signal, projecting the square of the received signal onto multiple components of an analogue signal basis in order to obtain an analogue vector of dimension equal to the number of projection components, the components of the analogue signal basis being non-constant functions, digitizing the analogue vector into a digital vector, jointly demodulating the components of the digital vector by way of a maximum likelihood algorithm in order to estimate the transmitted sequence of one or more consecutive digital symbols.

A method for receiving a modulated signal, includes the steps of receiving a signal modulated by a pulse position modulation (PPM) or a pulse width modulation (PWM) or a pulse amplitude modulation (PAM) or an on-off keying (OOK) amplitude modulation, corresponding to the transmission of a sequence of one or more consecutive digital symbols, squaring the received signal, projecting the square of the received signal onto multiple components of an analogue signal basis in order to obtain an analogue vector of dimension equal to the number of projection components, the components of the analogue signal basis being non-constant functions, digitizing the analogue vector into a digital vector, jointly demodulating the components of the digital vector by way of a maximum likelihood algorithm in order to estimate the transmitted sequence of one or more consecutive digital symbols.

In accordance with an embodiment, a device configured to detect a presence of at least one digital pattern within a signal includes J memory circuits having respectively Nj memory locations; and processing circuitry comprising an accumulator configured to successively address the memory locations of the J memory circuits in a circular manner at frequency F and during an acquisition time, and successively accumulate and store values indicative of a signal intensity in parallel in the J addressed memory locations of the J memory circuits, and a detector configured to detect the possible presence of the at least one pattern.

This application provides communication apparatuses and methods for signal transmission and reception, applied to, for example, backscatter communications. In an example method, a tag device receives a downlink excitation signal, where the downlink excitation signal is a linear frequency modulated signal or a multi-carrier linear frequency modulated signal. The tag device generates an uplink reflection signal according to the downlink excitation signal and uplink information. The tag device sends the uplink reflection signal to a network device. When receiving the uplink reflection signal from the tag device and receiving the downlink excitation signal, the network device performs fractional Fourier transform on the uplink reflection signal and the downlink excitation signal, to obtain an uplink frequency domain reflection signal and a downlink frequency domain excitation signal. The uplink frequency domain reflection signal and the downlink frequency domain excitation signal do not overlap each other.

This application provides communication apparatuses and methods for signal transmission and reception, applied to, for example, backscatter communications. In an example method, a tag device receives a downlink excitation signal, where the downlink excitation signal is a linear frequency modulated signal or a multi-carrier linear frequency modulated signal. The tag device generates an uplink reflection signal according to the downlink excitation signal and uplink information. The tag device sends the uplink reflection signal to a network device. When receiving the uplink reflection signal from the tag device and receiving the downlink excitation signal, the network device performs fractional Fourier transform on the uplink reflection signal and the downlink excitation signal, to obtain an uplink frequency domain reflection signal and a downlink frequency domain excitation signal. The uplink frequency domain reflection signal and the downlink frequency domain excitation signal do not overlap each other.

There is described an RFID IC, comprising:

i) an RFID interface configured to receive a digitally modulated signal, wherein the digitally modulated signal comprises: a first slot with a first pulse, and a second slot with a second pulse; and
ii) a processing unit configured to
a) determine a first position of the first pulse in the first slot,
b) filter a region that follows the determined first position of the first pulse,
c) determine a second position of the second pulse in the second slot, and, if the second position of the second pulse cannot be determined in the second slot, assume that the second position of the second pulse in the second slot is at the filtered region.

There is described an RFID IC, comprising:

i) an RFID interface configured to receive a digitally modulated signal, wherein the digitally modulated signal comprises: a first slot with a first pulse, and a second slot with a second pulse; and
ii) a processing unit configured to
a) determine a first position of the first pulse in the first slot,
b) filter a region that follows the determined first position of the first pulse,
c) determine a second position of the second pulse in the second slot, and, if the second position of the second pulse cannot be determined in the second slot, assume that the second position of the second pulse in the second slot is at the filtered region.

A wireless receiver system includes a receiver antenna, a sensor, a demodulation circuit, and a receiver controller. The sensor is configured to detect electrical information associated with AC wireless signals, the electrical information including, at least, a voltage of the AC wireless signals. The demodulation circuit is configured to receive the electrical information from the at least one sensor, detect a change in the electrical information, determine if the change in the electrical information meets or exceeds one of a rise threshold or a fall threshold, if the change exceeds one of the rise threshold or the fall threshold, generate an alert, and output a plurality of data alerts. The receiver controller is configured to receive the plurality of data alerts from the demodulation circuit, and decode the plurality of data alerts into the wireless data signals.