In one implementation, a wireless communication device includes a first transceiver configured to generate a transmit signal and a band pass filter (BPF) select circuit configured to filter the transmit signal by a one of a first BPF with a relatively high-frequency passband or a second BPF with a relatively low-frequency passband. The wireless communication device includes a second transceiver configured to receive a received signal filtered by the other one of the first or second BPF. Having the transmit and received signals filtered by two different passband filters improves the isolation between the transmitter and receiver. Another implementation configures the first transceiver to include its own set of first and second BPFs, and the second transceiver to also include its own first and second BPFs.

The embodiments described herein are directed at techniques to de-correlate Bluetooth interference seen across WLAN receive antennas/space in a Bluetooth transceiver/WLAN transceiver combination device. A Bluetooth interference whitening technique may be utilized, wherein a whitening matrix is computed based on a leakage signal resulting from a training signal transmitted by the Bluetooth transceiver. The leakage signal may leak in to the WLAN transceiver and a set of attributes is calculated for each frequency the leakage signal is received on. One or more whitening matrixes are calculated based on the set of attributes for each frequency the leakage signal is received on. In response to the WLAN transceiver receiving a signal of interest, an appropriate whitening matrix from the one or more whitening matrixes is selected and is then applied to the received signal of interest to de-correlate any interference generated as a result of the Bluetooth transmission.

The embodiments described herein are directed at techniques to de-correlate Bluetooth interference seen across WLAN receive antennas/space in a Bluetooth transceiver/WLAN transceiver combination device. A Bluetooth interference whitening technique may be utilized, wherein a whitening matrix is computed based on a leakage signal resulting from a training signal transmitted by the Bluetooth transceiver. The leakage signal may leak in to the WLAN transceiver and a set of attributes is calculated for each frequency the leakage signal is received on. One or more whitening matrixes are calculated based on the set of attributes for each frequency the leakage signal is received on. In response to the WLAN transceiver receiving a signal of interest, an appropriate whitening matrix from the one or more whitening matrixes is selected and is then applied to the received signal of interest to de-correlate any interference generated as a result of the Bluetooth transmission.

Examples described herein include systems and methods which include wireless devices and systems with examples of full duplex compensation with a self-interference noise calculator that compensates for the self-interference noise generated by power amplifiers at harmonic frequencies of a respective wireless receiver. The self-interference noise calculator may be coupled to antennas of a wireless device and configured to generate the adjusted signals that compensate self-interference. The self-interference noise calculator may include a network of processing elements configured to combine transmission signals into sets of intermediate results. Each set of intermediate results may be summed in the self-interference noise calculator to generate a corresponding adjusted signal. The adjusted signal is receivable by a corresponding wireless receiver to compensate for the self-interference noise generated by a wireless transmitter transmitting on the same or different frequency band as the wireless receiver is receiving.

Examples described herein include systems and methods which include wireless devices and systems with examples of full duplex compensation with a self-interference noise calculator that compensates for the self-interference noise generated by power amplifiers at harmonic frequencies of a respective wireless receiver. The self-interference noise calculator may be coupled to antennas of a wireless device and configured to generate the adjusted signals that compensate self-interference. The self-interference noise calculator may include a network of processing elements configured to combine transmission signals into sets of intermediate results. Each set of intermediate results may be summed in the self-interference noise calculator to generate a corresponding adjusted signal. The adjusted signal is receivable by a corresponding wireless receiver to compensate for the self-interference noise generated by a wireless transmitter transmitting on the same or different frequency band as the wireless receiver is receiving.

A method of a first communication device for removing a self-interference signal in a wireless communication system is provided. The method includes receiving a signal having a size less than a first threshold value from a second communication device in a first interval within a first frame, transmitting a first signal to a third communication device in the first interval, and estimating a self-interference channel through which the self-interference signal is transmitted based on the signal received in the first interval and the first signal transmitted in the first interval. The self-interference signal is a signal transmitted by the first communication device and is received by the first communication device through the self-interference channel.

A method of a first communication device for removing a self-interference signal in a wireless communication system is provided. The method includes receiving a signal having a size less than a first threshold value from a second communication device in a first interval within a first frame, transmitting a first signal to a third communication device in the first interval, and estimating a self-interference channel through which the self-interference signal is transmitted based on the signal received in the first interval and the first signal transmitted in the first interval. The self-interference signal is a signal transmitted by the first communication device and is received by the first communication device through the self-interference channel.

Radio frequency (RF) systems with tunable filters are provided herein. In certain embodiments, an RF system includes a first RF processing circuit configured to process a first frequency band of a first communication standard and a second frequency band of a second communication standard. The first frequency band and the second frequency band are close in frequency and/or partially overlapping in frequency. The first RF processing circuit includes a tunable filter for changing the bandwidth of the first RF processing circuit to enhance the robustness of the first RF processing circuit to blocker or jammer signals of a third frequency band.

A cross-division duplex (XDD) system includes an apparatus having a transceiver configured to communicate via an uplink channel and a downlink channel concurrently. The apparatus also includes a transmit antenna, a receive antenna, and a processor. The processor is configured to: estimate a non-linear component corresponding to a transmit path in the transceiver; apply an equalizer function to a received signal; and subtract, in a self-interference cancel (SIC) circuitry, the estimated non-linear component from the equalized signal.

A cross-division duplex (XDD) system includes an apparatus having a transceiver configured to communicate via an uplink channel and a downlink channel concurrently. The apparatus also includes a transmit antenna, a receive antenna, and a processor. The processor is configured to: estimate a non-linear component corresponding to a transmit path in the transceiver; apply an equalizer function to a received signal; and subtract, in a self-interference cancel (SIC) circuitry, the estimated non-linear component from the equalized signal.