An electronic device according to a disclosed embodiment includes a first antenna, a second antenna, a first communication circuit configured to communicate in a first frequency band with the first antenna at a first data rate, a second communication circuit configured to communicate in a second frequency band with the second antenna at a second data rate, a first coupler electrically connected between the first antenna and the first communication circuit, and at least one communication circuit configured to control to identify, during at least part of a period of simultaneously transmitting a first transmit signal with the first antenna and a second transmit signal with the second antenna, an amplitude of a first receive signal including at least part of the second transmit signal detected by the first coupler, disable an operation of attenuating the at least part of the second transmit signal included in the first receive signal based on the amplitude of the first receive signal falling in a first designated range, and enable the operation of attenuating the at least part of the second transmit signal included in the first receive signal based on the amplitude of the first receive signal falling in a second designated range.

A system includes a transmit equalizer to equalize a data stream using a set of transmit parameters to generate an input signal. The system further includes a communication channel to receive the input signal. The system further includes a receive equalizer to receive an output signal from the communication channel in response to the input signal and detect the data stream from the output signal using a set of receive parameters. The system additionally includes a controller to change the set of transmit parameters in response to a condition, where the transmit parameters, the receive parameters, and the condition are selected to both enable the receive equalizer to detect the data stream from the output signal and reduce the likelihood of an external circuit detecting the data stream from the output signal.

This application discloses a communications chip structure, including: a channel selection module, configured to receive an input signal, where the input signal is a signal of a preset narrow bandwidth span or a signal of a preset wide bandwidth span; and a digital baseband module, configured to control the channel selection module to select a first sampling and quantification channel when the input signal is a signal of the preset narrow bandwidth span, or control the channel selection module to select a second sampling and quantification channel when the input signal is a signal of the preset wide bandwidth span. The channel selection module is further configured to send the input signal to the first sampling and quantification channel or the second sampling and quantification channel for sampling and quantification.

Systems and methods of transmitting direct detection optical signal are provided. A direct detection optical transmitter according to illustrative embodiments includes a Mach Zehnder Modulator (MZM) configured to modulate laser light based on an electrical drive signal to generate a modulated optical signal and a complementary-modulated optical signal. The optical transmitter includes an optical finite impulse response (FIR) filter configured to receive the complementary-modulated optical signal and generate a filtered optical signal. The optical transmitter includes a polarization rotator configured to receive the filtered optical signal and output a rotated optical signal. The optical transmitter includes an optical combiner configured to combine the modulated optical signal and the rotated optical signal. The optical transmitter includes an output port configured to output the combined optical signal.

Techniques and apparatus for optimizing transmitter equalization are described. An example technique includes capturing a single output signal transmitted from a port on at least one channel of a host device. An impulse response of the channel is determined based at least in part on the single output signal. A transmitter feedforward equalization (FFE) is generated, based at least in part on the impulse response of the channel. The transmitter FFE is applied to the channel of the port of the host device.

A transmission apparatus that transmits a block signal including a plurality of data symbols, includes: a data-symbol generation unit that generates a data symbol; a symbol arrangement unit that arranges the data symbol and a same-quadrant symbol such that one same-quadrant symbol that becomes a signal point in a same quadrant in a complex plane is inserted per block at a predetermined position in each block signal to generate a block symbol; a CP insertion unit that inserts a Cyclic Prefix into the block symbol; and an interpolation unit that performs interpolation processing on the block symbol on which CP insertion has been performed.

A transmit/receive signal processor for Wireless Local Area Network (WLAN) and Bluetooth has selectable signal processing elements for mixers, Intermediate Frequency (IF) filters, transmit power amplifiers, and clock sources which are suitable for either Bluetooth or WLAN signal processing. The operating mode of the signal processor is selected to be one of Wireless High Performance, Wireless Low Power, Bluetooth High Performance or Bluetooth Low power, and the signal processing modules are selected to provide performance or power requirements using selected modules.

A signal generator 10 generates an OOK (on-off keying) modulation signal by mapping a CAZAC (constant amplitude zero auto-correlation) sequence to N subcarriers (N being an integer that is greater than or equal to 2) arranged at a determined interval among M subcarriers (M being an integer that is greater than or equal to 3) that are adjacent in the frequency domain, carrying out inverse fast Fourier transform (IFFT) processing on the mapped CAZAC sequence, and carrying out Manchester coding on a time domain signal generated by the IFFT processing. A radio transmitter 107 transmits the OOK modulation signal.

An apparatus for wireless transmissions and reception. The apparatus includes a radio frequency (RF) circuitry, a baseband circuitry, and a conversion circuitry. The RF circuitry is configured to transmit and receive a signal in an RF frequency. The baseband circuitry is configured to process a transmit signal or a receive signal in a baseband frequency. The conversion circuitry is configured to perform frequency conversion between the baseband and RF frequencies. The conversion circuitry is configured to convert a baseband signal received from the baseband circuitry to an RF signal in a first RF frequency if a transmit frequency is a second RF frequency or to the RF signal in the second RF frequency if the transmit frequency is the first RF frequency, and send the RF signal after frequency conversion to the RF circuitry. The RF circuitry converts the received RF signal to the transmit frequency for transmission.

Apparatus and methods related to multipath bandpass filters with passband notches are provided herein. In certain configurations, a multipath bandpass filter includes multiple filter circuit branches or paths that are electrically connected in parallel with one another between an input terminal and an output terminal. The input terminal receives an input signal, and each filter circuit branch includes a downconverter that downconverts the input signal to generate a downconverted signal, a filter network that generates a filtered signal by filtering the downconverted signal, and an upconverter that upconverts the filtered signal to generate a branch output signal. The filter network includes at least one low pass filter and at least one notch filter to provide a passband with in-band notches. The branch output signals from the filter circuit branches are combined to generate an output signal at the output terminal.