Abstract: A hybrid method of estimating position of a mobile device which utilizes both received signal power and timing measurements. Received signal power of signals received by the mobile device from a plurality of cells are measured and corresponding received signal power measurements are stored. The method further includes measuring, at the mobile device, times of arrival of signals received from the plurality of cells. A plurality of time difference of arrival (TDOA) measurements are determined from the times of arrival. A power-time hybrid Gaussian maximum likelihood estimator and positioning assistance data for the plurality of cells are used to generate a maximum likelihood estimate of the position of the mobile device by evaluating a joint conditional probability of the received signal power measurements and the plurality of TDOA measurements. Gaussian random variables may be used to represent the received signal power measurements and the TDOA measurements.

Abstract: This disclosure provides systems, methods and apparatuses for classifying traffic flow using a plurality of learning machines arranged in multiple hierarchical levels. A first learning machine may classify a first portion of the input stream as malicious based on a match with first classification rules, and a second learning machine may classify at least part of the first portion of the input stream as malicious based on a match with second classification rules. The at least part of the first portion of the input stream may be classified as malicious based on the matches in the first and second learning machines.

Abstract: This disclosure provides systems, methods and apparatuses for classifying traffic flow using a plurality of learning machines arranged in multiple hierarchical levels. A first learning machine may classify a first portion of the input stream as malicious based on a match with first classification rules, and a second learning machine may classify at least part of the first portion of the input stream as malicious based on a match with second classification rules. The at least part of the first portion of the input stream may be classified as malicious based on the matches in the first and second learning machines.

Abstract: A method for estimating position of a mobile device which includes receiving, from a network server, observed time difference of arrival (OTDOA) assistance data for a first plurality of cells from a base station almanac (BSA) accessible to the network server. The OTDOA assistance data is stored, within a memory of the mobile device, as a first micro-BSA. A position estimate for the mobile device is determined based upon time difference of arrival (TDOA) measurements associated with an initial subset of the first plurality of cells and initial OTDOA assistance data corresponding to the initial subset of the first plurality of cells. The initial OTDOA assistance data may be generated by the micro-BSA based upon an initial seed estimate.

Abstract: A wireless receiver receives location pilots embedded in received symbols and uses the location pilots to detect the first path for every base station the network has designated for the receiver to use in time of arrival estimation. The receiver preferably applies matching pursuit strategies to offer a robust and reliable identification of a channel impulse response's first path. The receiver may also receive and use estimation pilots as a supplement to the location pilot information in determining time of arrival. The receiver can use metrics characteristic of the channel to improve the robustness and reliability of the identification of a CIR's first path. With the first path identified, the receiver measures the time of arrival for signals from that path and the receiver determines the observed time difference of arrival (OTDOA) to respond to network requests for OTDOA and position determination measurements.

Abstract: A method for estimating position of a mobile device which includes receiving, from a network server, observed time difference of arrival (OTDOA) assistance data for a first plurality of cells from a base station almanac (BSA) accessible to the network server. The OTDOA assistance data is stored, within a memory of the mobile device, as a first micro-BSA. A position estimate for the mobile device is determined based upon time difference of arrival (TDOA) measurements associated with an initial subset of the first plurality of cells and initial OTDOA assistance data corresponding to the initial subset of the first plurality of cells. The initial OTDOA assistance data may be generated by the micro-BSA based upon an initial seed estimate.

Abstract: A hybrid method of estimating position of a mobile device which utilizes both received signal power and timing measurements. Received signal power of signals received by the mobile device from a plurality of cells are measured and corresponding received signal power measurements are stored. The method further includes measuring, at the mobile device, times of arrival of signals received from the plurality of cells. A plurality of time difference of arrival (TDOA) measurements are determined from the times of arrival. A power-time hybrid Gaussian maximum likelihood estimator and positioning assistance data for the plurality of cells are used to generate a maximum likelihood estimate of the position of the mobile device by evaluating a joint conditional probability of the received signal power measurements and the plurality of TDOA measurements. Gaussian random variables may be used to represent the received signal power measurements and the TDOA measurements.

Abstract: A wireless receiver receives location pilots embedded in received symbols and uses the location pilots to detect the first path for every base station the network has designated for the receiver to use in time of arrival estimation. The receiver preferably applies matching pursuit strategies to offer a robust and reliable identification of a channel impulse response's first path. The receiver may also receive and use estimation pilots as a supplement to the location pilot information in determining time of arrival. The receiver can use metrics characteristic of the channel to improve the robustness and reliability of the identification of a CIR's first path. With the first path identified, the receiver measures the time of arrival for signals from that path and the receiver determines the observed time difference of arrival (OTDOA) to respond to network requests for OTDOA and position determination measurements.

Abstract: A wireless receiver receives location pilots embedded in received symbols and uses the location pilots to detect the first path for every base station the network has designated for the receiver to use in time of arrival estimation. The receiver preferably applies matching pursuit strategies to offer a robust and reliable identification of a channel impulse response's first path. The receiver may also receive and use estimation pilots as a supplement to the location pilot information in determining time of arrival. The receiver can use metrics characteristic of the channel to improve the robustness and reliability of the identification of a CIR's first path. With the first path identified, the receiver measures the time of arrival for signals from that path and the receiver determines the observed time difference of arrival (OTDOA) to respond to network requests for OTDOA and position determination measurements.

Abstract: A method for estimating position of a mobile device which includes receiving, from a network server, observed time difference of arrival (OTDOA) assistance data for a first plurality of cells from a base station almanac (BSA) accessible to the network server. The OTDOA assistance data is stored, within a memory of the mobile device, as a first micro-BSA. A position estimate for the mobile device is determined based upon time difference of arrival (TDOA) measurements associated with an initial subset of the first plurality of cells and initial OTDOA assistance data corresponding to the initial subset of the first plurality of cells. The initial OTDOA assistance data may be generated by the micro-BSA based upon an initial seed estimate.

Abstract: A wireless receiver receives location pilots embedded in received symbols and uses the location pilots to detect the first path for every base station the network has designated for the receiver to use in time of arrival estimation. The receiver preferably applies matching pursuit strategies to offer a robust and reliable identification of a channel impulse response's first path. The receiver may also receive and use estimation pilots as a supplement to the location pilot information in determining time of arrival. The receiver can use metrics characteristic of the channel to improve the robustness and reliability of the identification of a CIR's first path. With the first path identified, the receiver measures the time of arrival for signals from that path and the receiver determines the observed time difference of arrival (OTDOA) to respond to network requests for OTDOA and position determination measurements.

Abstract: A wireless receiver receives location pilots embedded in received symbols and uses the location pilots to detect the first path for every base station the network has designated for the receiver to use in time of arrival estimation. The receiver preferably applies matching pursuit strategies to offer a robust and reliable identification of a channel impulse response's first path. The receiver may also receive and use estimation pilots as a supplement to the location pilot information in determining time of arrival. The receiver can use metrics characteristic of the channel to improve the robustness and reliability of the identification of a CIR's first path. With the first path identified, the receiver measures the time of arrival for signals from that path and the receiver determines the observed time difference of arrival (OTDOA) to respond to network requests for OTDOA and position determination measurements.

Abstract: A wireless receiver receives location pilots embedded in received symbols and uses the location pilots to detect the first path for every base station the network has designated for the receiver to use in time of arrival estimation. The receiver preferably applies matching pursuit strategies to offer a robust and reliable identification of a channel impulse response's first path. The receiver may also receive and use estimation pilots as a supplement to the location pilot information in determining time of arrival. The receiver can use metrics characteristic of the channel to improve the robustness and reliability of the identification of a CIR's first path. With the first path identified, the receiver measures the time of arrival for signals from that path and the receiver determines the observed time difference of arrival (OTDOA) to respond to network requests for OTDOA and position determination measurements.

Abstract: An OFDM communication system performs time domain channel estimation responsive to received symbols before the symbols are processed by a fast Fourier transform. The communication system generates virtual pilots from actual pilots to improve the stability and quality of channel estimation. The system generates a reference signal from the actual and virtual pilots and correlates the resulting reference signal with a signal responsive to the received symbol to generate an initial channel impulse response (CIR) and to determine statistics about the channel. In some circumstances, the resulting reference signal is correlated with a modified symbol in which the actual and virtual pilot locations are emphasized and the data locations are deemphasized. Time domain channel estimation iteratively improves on the initial CIR. The system determines channel estimates for data only symbols through averaging such as interpolation.

Abstract: An OFDM receiver receives OFDM symbols in the frequency domain and comb filters and then punctures the OFDM symbols to leave symbols with actual pilot information and with null values at the data symbols. The receiver provides the punctured OFDM symbols to an OFDM symbol queue. A virtual pilot interpolator is coupled to the punctured OFDM symbol storage to generate virtual pilot information introduced to OFDM symbols. The interpolator may be a two dimensional Wiener filter. The receiver also includes a time domain channel estimator that processes a first OFDM symbol including virtual pilot information to generate a channel impulse response for the first OFDM symbol. A frequency equalizer equalizes the OFDM symbol in response to the channel impulse response for the first OFDM symbol.

Abstract: An OFDM receiver generates an initial channel impulse response in response to a received OFDM signal. The receiver determines the time span within the initial channel impulse response in which significant paths are present. An intermediate channel impulse response estimator identifies paths within the initial channel impulse response and generates an improved intermediate channel impulse response. A channel impulse response estimator performs a second non-linear process to generate a channel impulse response. An equalizer responds to the channel impulse response and the OFDM symbol to equalize the OFDM symbol. Metrics are generated that can be used for effectively stopping the second iterative non-linear process.

Abstract: A software upgrade application can be downloaded to a handset to selectively enable enhanced functionality physical layer circuitry. In a particular implementation, an OFDM handset or other portable modem includes selectively enabled time domain channel estimation circuitry. An upgrade application within the handset is activated. The handset is checked to confirm compatibility with the enhanced functionality and the upgrade application is checked to confirm its authenticity. The upgrade application then activates the enhanced functionality within the physical layer of the device.

Abstract: An OFDM receiver receives OFDM symbols in the frequency domain and comb filters and then punctures the OFDM symbols to leave symbols with actual pilot information and with null values at the data symbols. The receiver provides the punctured OFDM symbols to an OFDM symbol queue. A virtual pilot interpolator is coupled to the punctured OFDM symbol storage to generate virtual pilot information introduced to OFDM symbols. The interpolator may be a two dimensional Wiener filter. The receiver also includes a time domain channel estimator that processes a first OFDM symbol including virtual pilot information to generate a channel impulse response for the first OFDM symbol. A frequency equalizer equalizes the OFDM symbol in response to the channel impulse response for the first OFDM symbol.

Abstract: An OFDM receiver receives OFDM symbols in the frequency domain and comb filters and then punctures the OFDM symbols to leave symbols with actual pilot information and with null values at the data symbols. The receiver provides the punctured OFDM symbols to an OFDM symbol queue. A virtual pilot interpolator is coupled to the punctured OFDM symbol storage to generate virtual pilot information introduced to OFDM symbols. The interpolator may be a two dimensional Wiener filter. The receiver also includes a time domain channel estimator that processes a first OFDM symbol including virtual pilot information to generate a channel impulse response for the first OFDM symbol. A frequency equalizer equalizes the OFDM symbol in response to the channel impulse response for the first OFDM symbol.

Abstract: An OFDM communication system performs time domain channel estimation responsive to received symbols before the symbols are processed by a fast Fourier transform. The communication system generates virtual pilots from actual pilots to improve the stability and quality of channel estimation. The system generates a reference signal from the actual and virtual pilots and correlates the resulting reference signal with a signal responsive to the received symbol to generate an initial channel impulse response (CIR) and to determine statistics about the channel. In some circumstances, the resulting reference signal is correlated with a modified symbol in which the actual and virtual pilot locations are emphasized and the data locations are deemphasized. Time domain channel estimation iteratively improves on the initial CIR. The system determines channel estimates for data only symbols through averaging such as interpolation.