A subchannel detection system for a wireless communication device is disclosed. The system includes an input interface arranged to receive digital data over a predetermined baseband having a plurality of subchannels a plurality of frequency translators arranged to shift the spectrum of the digital data within a subchannel to the center of the baseband, a plurality of low-pass filters arranged to filter frequencies in the middle of the baseband within a subchannel bandwidth, a plurality of correlators arranged to receive a filtered digital signal and correlate the received signal to a subchannel size, and a processing module arranged to receive data from the plurality of correlators and detect one or more active subchannels. The plurality of frequency translators shift the spectrum of all subchannels in the digital data to the center of the baseband; the shifted spectra are filtered by the plurality of low-pass filters and correlated to individual subchannels.

A radio-frequency (RF) sampling transmitter (e.g., of the type that may be used in 5G wireless base stations) includes a complex baseband digital-to-analog converter (DAC) response compensator that operates on a complex baseband signal at a sampling rate lower than the sampling rate of an RF sampling DAC in the RF sampling transmitter. The DAC response compensator flattens the sample-and-hold response of the RF sampling DAC only in the passband of interest, addressing the problem of a sinc response introduced by the sample-and-hold operation of the RF sampling DAC and avoiding the architectural complexity and high power consumption of an inverse sinc filter that operates on the signal at a point in the signal chain after it has already been up-converted to an RF passband.

The disclosed embodiments provide an absorptive coupled-line bandpass filter. This bandpass filter includes a first port, which is coupled to a first absorptive stub, and a second port, which is coupled to a second absorptive stub. The bandpass filter also includes a coupled-line bandpass section coupled between the first and second ports, wherein the coupled-line bandpass section comprises a set of one or more parallel strip line resonators, which are coupled together in series and are coupled to the first and second ports through overlapping coupled-line sections, wherein at a center frequency of a passband for the absorptive coupled-line bandpass filter, the first and second absorptive stubs appear as open circuits, and outside of the passband, the first and second absorptive stubs appear as matched loads to ground and contribute to absorption of out-of-band signals.

A radio-frequency (RF) sampling transmitter (e.g., of the type that may be used in 5G wireless base stations) includes a complex baseband digital-to-analog converter (DAC) response compensator that operates on a complex baseband signal at a sampling rate lower than the sampling rate of an RF sampling DAC in the RF sampling transmitter. The DAC response compensator flattens the sample-and-hold response of the RF sampling DAC only in the passband of interest, addressing the problem of a sin c response introduced by the sample-and-hold operation of the RF sampling DAC and avoiding the architectural complexity and high power consumption of an inverse sin c filter that operates on the signal at a point in the signal chain after it has already been up-converted to an RF passband.

Devices and systems useful in concurrently receiving and transmitting Wi-Fi signals and Bluetooth signals in the same frequency band are provided. By way of example, an electronic device includes a transceiver configured to transmit data and to receive data over channels of a first wireless network and a second wireless network concurrently. The transceiver includes a plurality of filters configured to allow the transceiver to transmit the data and to receive the data in the same frequency band by reducing interference between signals of the first wireless network and the second wireless network.

A subchannel detection system for a wireless communication device is disclosed. The system includes an input interface arranged to receive digital data over a predetermined baseband having a plurality of subchannels a plurality of frequency translators arranged to shift the spectrum of the digital data within a subchannel to the center of the baseband, a plurality of low-pass filters arranged to filter frequencies in the middle of the baseband within a subchannel bandwidth, a plurality of correlators arranged to receive a filtered digital signal and correlate the received signal to a subchannel size, and a processing module arranged to receive data from the plurality of correlators and detect one or more active subchannels. The plurality of frequency translators shift the spectrum of all subchannels in the digital data to the center of the baseband; the shifted spectra are filtered by the plurality of low-pass filters and correlated to individual subchannels.

A high frequency (HF) radio configured to process an incoming call from another HF radio, the HF radio comprising: an adjustable-bandwidth tunable bandpass filter configured to provide HF signals that are within an adjustable-bandwidth Staring Frequency Band (SFB), being a subset of a HF band, the HF signals including analog calling signals that are indicative of incoming calls; a receive path configured to convert the analog calling signals to digital calling signals; a plurality of receivers configured to monitor assigned Automatic Link Establishment (ALE) channels within the SFB for the digital calling signals; and a controller configured to: establish a communication link between the HF radio and the another HF radio, in response to a given receiver of the receivers decoding a digital calling signal that is indicative of the incoming call; and select the SFB and the assigned ALE channels, based on an indication of ionospheric propagation conditions.

A head end unit of a distributed antenna system includes circuitry configured to: receive downlink signals from at least one base station; process the downlink signals into downlink channelized digital baseband signals at the head end unit by at least one of mixing, decimating, and filtering the downlink channelized digital baseband signals including call information for wireless communication; format the downlink channelized digital baseband signals for transport together; packetize and packet schedule the downlink channelized digital baseband signals into downlink packetized baseband signals at the head end unit; and transmit the downlink packetized baseband signals from the head end unit to remotely located units of the distributed antenna system.

Systems, methods and devices to generate tailored antenna radiation patterns for particular purposes are provided. The software-defined communication devices and systems dynamically reconfigure an antenna in a controlled and reversible manner, transmit and receive signals to a plurality of endpoints simultaneously without requiring moving elements, and control radiation patterns, making them useful and more versatile for many applications, especially in implementations concerning satellite communications. Communication links may be established with multiple endpoints simultaneously, and the position of the endpoints may be learned without knowing it in advance. The configurations described in the embodiments provide great versatility due to the possibility of processing the signal at each antenna element of the antenna.

A method may comprise receiving and sampling a signal. The signal may encode a data packet. A slice may be generated and stored comprising a pair of values for each of a selected number of samples of the signal representing a correlation of the signal to reference functions in the receiver. The presence of the data packet may then be detected and the detected packet decoded from the stored slices. The generating and storing slices may be carried out as the received signal is sampled. The sampled values of the signal may be discarded as the slices are generated and stored. The slice representation of the signal can be manipulated to generate filters with flexible bandwidth and center frequency.