Abstract: Arbitration between two wireless protocols in a wireless device. The wireless device may include first wireless protocol circuitry, configured to receive and process first signals according to a first wireless protocol and second wireless protocol circuitry, configured to receive and process second signals according to a second wireless protocol. The wireless device may also include coexistence circuitry. The coexistence circuitry may be configured to receive a request from the first wireless protocol circuitry to perform transmission or reception and arbitrate the requested transmission or reception between the first wireless protocol circuitry and the second wireless protocol circuitry. The decision may be based on current or future priority information, current configuration, or other factors. The coexistence circuitry (or other circuitry) may be configured to determine position of switches controlling antennas or transmission using shared or unshared antennas (or chains).

Abstract: Arbitration between two wireless protocols in a wireless device. The wireless device may include first wireless protocol circuitry, configured to receive and process first signals according to a first wireless protocol and second wireless protocol circuitry, configured to receive and process second signals according to a second wireless protocol. The wireless device may also include coexistence circuitry. The coexistence circuitry may be configured to receive a request from the first wireless protocol circuitry to perform transmission or reception and arbitrate the requested transmission or reception between the first wireless protocol circuitry and the second wireless protocol circuitry. The decision may be based on current or future priority information, current configuration, or other factors. The coexistence circuitry (or other circuitry) may be configured to determine position of switches controlling antennas or transmission using shared or unshared antennas (or chains).

Abstract: Arbitration between two wireless protocols in a wireless device. The wireless device may include first wireless protocol circuitry, configured to receive and process first signals according to a first wireless protocol and second wireless protocol circuitry, configured to receive and process second signals according to a second wireless protocol. The wireless device may also include coexistence circuitry. The coexistence circuitry may be configured to receive a request from the first wireless protocol circuitry to perform transmission or reception and arbitrate the requested transmission or reception between the first wireless protocol circuitry and the second wireless protocol circuitry. The decision may be based on current or future priority information, current configuration, or other factors. The coexistence circuitry (or other circuitry) may be configured to determine position of switches controlling antennas or transmission using shared or unshared antennas (or chains).

Abstract: A method of identifying radar in a wireless device includes detecting an event corresponding to receipt of a signal by the wireless device. The event can include an analog to digital converter (ADC) saturation, a radio frequency (RF) saturation, and/or an ADC power high condition. Notably, the gain change in the wireless device is delayed for a first predetermined time period. Data preceding the event for the first predetermined time period can be buffered. A first low-resolution fast Fourier transform (FFT), wherein low-resolution FFTs are referred to as short FFTs, can be performed with the buffered data. The first short FFT can be processed. When results of the processing indicate the signal is radar, the radar can then be identified.

Abstract: This disclosure is directed to wireless communication systems having a receiver capable of detecting chirping radar pulses. The systems and methods include processing an input signal to obtain a spectral analysis that identifies which frequency exhibits maximum signal magnitude at a given time and determines a rate of change that frequency. By determining that the rate of change is within parameters established by the pulse width range and the chirping bandwidth range, the signal can be identified as a chirping radar pulse. By comparing the rate of change to known characteristics, the signal can be identified as a chirping radar pulse. Suitable characteristics include parameters for the rate of change established by the pulse width range and the chirping bandwidth range and linearity of the rate of change.

Abstract: Arbitration between two wireless protocols in a wireless device. The wireless device may include first wireless protocol circuitry, configured to receive and process first signals according to a first wireless protocol and second wireless protocol circuitry, configured to receive and process second signals according to a second wireless protocol. The wireless device may also include coexistence circuitry. The coexistence circuitry may be configured to receive a request from the first wireless protocol circuitry to perform transmission or reception and arbitrate the requested transmission or reception between the first wireless protocol circuitry and the second wireless protocol circuitry. The decision may be based on current or future priority information, current configuration, or other factors. The coexistence circuitry (or other circuitry) may be configured to determine position of switches controlling antennas or transmission using shared or unshared antennas (or chains).

Abstract: System and method for detecting radio frequency (RF) saturation in a wireless device configured to simultaneously receive first signals according to a first wireless protocol and second signals according to a second wireless protocol. Signals having components of both the first and second signals may be received at a shared gain element. A level of saturation of the shared gain element may be determined. A current definition of a saturation event may be determined. A gain adjustment value may be determined based on the level of saturation and the current definition of a saturation event. A gain value of the shared gain element may be adjusted by the determined gain adjustment value.

Abstract: A communication device supporting multiple wireless protocols may share a common gain element in a coordinated manner. A first wireless protocol circuitry of the communication device may enter an active state, and in response to entering the active state, may determine whether a second wireless protocol circuitry of the communication device is active and whether the common gain element is currently shared. The gain element may be adjustable to amplify signals by an adjustable amount. The first wireless protocol circuitry may take control of the gain element from the second wireless protocol circuitry in response to determining that the second wireless protocol circuitry is active and the gain element is currently shared.

Abstract: Limiting gain for simultaneously receiving first wireless signals according to a first wireless protocol and second wireless signals according to a second wireless protocol. The first signals may be received using a shared gain element. The shared gain element may be used by the first wireless protocol and the second wireless protocol. A transmission or reception of the second signals may be predicted. The transmission or reception of the second signals may be predicted for transmission or reception while receiving the first signals. Gain of the shared gain element may be limited based on the prediction.

Abstract: Spectrum sensing is one of the most challenging problems in cognitive radio systems. The spectrum of interest needs to be characterized and unused frequencies should be identified for possible exploitation in a simple and fast way, allowing the radio to catch up with the changing transmission parameters. A sensing method is presented where primary users are identified by matching the features extracted from the received signal to the a priori information about primary users' transmission characteristics. For estimation of some signal parameters, the cyclostationarity of the transmission spectrum is explored by using a suboptimal maximum likelihood (ML) estimator. The proposed algorithms can be used in cognitive radio for identifying various transmissions and for electronic surveillance.

Abstract: Methods for secure OFDM communications include changing the length of OFDM symbols in a pseudo-random fashion by appending a totally random signal to some of the OFDM symbols. An adaptive cyclic prefix is provided for covert and spectrally efficient communication. A developed PN based random data addition provides further security by removing the chance of combining synchronization information over several OFDM symbols.

Abstract: Arbitration between two wireless protocols in a wireless device. The wireless device may include first wireless protocol circuitry, configured to receive and process first signals according to a first wireless protocol and second wireless protocol circuitry, configured to receive and process second signals according to a second wireless protocol. The wireless device may also include coexistence circuitry. The coexistence circuitry may be configured to receive a request from the first wireless protocol circuitry to perform transmission or reception and arbitrate the requested transmission or reception between the first wireless protocol circuitry and the second wireless protocol circuitry. The decision may be based on current or future priority information, current configuration, or other factors. The coexistence circuitry (or other circuitry) may be configured to determine position of switches controlling antennas or transmission using shared or unshared antennas (or chains).

Abstract: A signal analysis mechanism for processing and classifying an RF signal received at a WLAN device. A plurality of spectral data captures comprising time-frequency data and receive signal strength indicator (RSSI) data associated with the RF signal received at the WLAN device are generated. The time-frequency and RSSI data of each of the plurality of spectral data captures is processed to determine whether each spectral data capture is a narrowband signal capture. If the plurality of spectral data captures are narrowband signal captures, a narrowband interference signal type associated with the received RF signal is determined based, at least in part, on a plurality of parameters associated with the narrowband signal captures.

Abstract: In accordance with the present invention, a method and apparatus for estimating the noise and interference over the transmission band for OFDM systems are provided. Noise variance and signal-to-noise ratio (SNR) are important parameters for adaptive orthogonal frequency division multiplexing (OFDM) systems since they serve as a standard measure of signal quality. Conventional algorithms assume that the noise statistics remain constant over the OFDM frequency band, and thereby average the instantaneous noise samples to get a single estimate. In reality, noise is often made up of white Gaussian noise along with correlated colored noise that affects the OFDM spectrum unevenly. Provided is an adaptive windowing technique to estimate the noise power that takes into account the variation of the noise statistics across the OFDM sub-carrier index as well as across OFDM symbols. The proposed method provides many local estimates, allowing tracking of the variation of the noise statistics in frequency and time.

Abstract: Methods for secure OFDM communications include changing the length of OFDM symbols in a pseudo-random fashion by appending a totally random signal to some of the OFDM symbols. An adaptive cyclic prefix is provided for covert and spectrally efficient communication. A developed PN based random data addition provides further security by removing the chance of combining synchronization information over several OFDM symbols.