Abstract:
Methods and systems for multi-path video and network channels may comprise a communication device comprising a wideband path (WB) and a narrowband path (NB), wherein the WB may be operable to receive a plurality of channels and the NB may be operable to receive a single channel. Video channels and a network channel may be received in the WB when the device is operating in a first stage. Video channels and a network channel may be received in the WB and the network channel may also be received in the NB when the device is operating in a second stage. The network channel may be received in the NB when the device is operating in a third stage. The reception of the network channel from both the WB and the NB may enable a continuous reception of the network channel in a transition between the first and third stages.
Abstract:
A signal receiver may be configured to determine when signal generation changes affecting signals being received by the signal receiver may cause performance related changes; and to modify its (the signal receiver) configuration to handle the performance related changes. In this regard, the modifying of configuration may comprise determining characteristics of performance related changes, and controlling operations of the signal receiver based on the determined characteristics of the performance related changes. The performance related changes may comprise amplitude glitches, phase glitches, and/or bit or packet errors. The signal generation changes may comprise channel-to-frequency re-assignment. Controlling operations of the signal receiver based on determined characteristics of the performance related changes may comprise adjusting such parameters as amplification gain and/or tracking loop bandwidth, and/or determining whether (or not) to ignore bit/packet errors—i.e. not reacquire (e.g., based on determination that tracking loops used in the signal receiver remain locked).
Abstract:
Systems and methods for adjusting timing in a communication system, such as an OFDM system are described. In one implementation an error signal is generated to adjust the timing of a variable rate interpolator so as to adjust FFT timing. The error signal may be based on detection of significant peaks in an estimate of the impulse response of the channel, with the peak locations being tracked over subsequent symbols and the system timing adjusted in response to changes in the peaks.
Abstract:
A GPS receiver includes an RF front end for acquiring and tracking a satellite signal and a baseband processor configured to preserve power. The baseband processor includes a GPS engine configured to process the satellite signal and generate a PVT fix, a power supervisory module for receiving the PVT fix, and a user state module that determines an environmental state, wherein the power supervisory module may power down the GPS receiver for a period of time based on a result of the determined environment state. The baseband processor also includes a time-based management module that adjusts the TCXO in response to the determined environmental state. The GPS receiver includes a plurality of operation modes, each of which is associated with a plurality of tracking profiles.
Abstract:
A decoder for a communication system includes an iterative decoding module configured to receive soft-input information bits. The iterative decoding module iterates on probability estimates of the soft-input information bits to generate hard-decision output information. The iterative decoding module includes a plurality of arithmetic modules operating to generate and process both backward and forward metrics substantially simultaneously using modulo arithmetic operations.
Abstract:
Methods and systems for repurposing of a global navigation satellite system receiver for receiving low-earth orbit (LEO) communication satellite timing signals may comprise receiving medium Earth orbit (MEO) satellite signals and/or LEO signals in a receiver of the communication device. A radio frequency (RF) path may be configured to down-convert either of the signals, and a position of the communication device may be calculated utilizing the down-converted signals. The signals may be down-converted utilizing a local oscillator signal generated by a phase locked loop (PLL), which may be delta-sigma modulated via a fractional-N divider. A clock signal may be communicated to the PLL utilizing a temperature-compensated crystal oscillator. The signals may be down-converted to an intermediate frequency or down-converted directly to baseband frequencies. The signals may be processed utilizing surface acoustic wave (SAW) filters. In-phase and quadrature signals may be processed in the RF path utilizing a two-stage polyphase filter.
Abstract:
A method and system for combining a guard interval and a corresponding portion of a received symbol, whereby when receiving a signal that contains the symbol with a guard interval corresponding to the symbol, a portion of the guard interval that is free from inter-symbol interference may be extracted, and the extracted portion of the guard interval may be combined with the corresponding portion of the symbol. The extracting and combining may be done after a determining, based on a delay profile provided by the received signal, that a delay spread is smaller than a predetermined channel delay. The delay spread may be determined by filtering an instantaneous delay spread associated with the received signal. The filtering may be performed using a 1-tap infinite impulse response low-pass filter. The low-pass filter may include a time constant that is the inverse of a maximum Doppler frequency shift.
Abstract:
Systems and methods for extracting synchronization information from ambient signals, such as broadcast television signals, and using the synchronization information as a reference for correcting the local time base so that a GNSS positioning receiver system maintains relative time base accuracy with respect to a GNSS time.
Abstract:
Methods and systems for multi-path video and network channels may comprise a communication device comprising a wideband path (WB) and a narrowband path (NB), wherein the WB may be operable to receive a plurality of channels and the NB may be operable to receive a single channel. Video channels and a network channel may be received in the WB when the device is operating in a first stage. Video channels and a network channel may be received in the WB and the network channel may also be received in the NB when the device is operating in a second stage. The network channel may be received in the NB when the device is operating in a third stage. The reception of the network channel from both the WB and the NB may enable a continuous reception of the network channel in a transition between the first and third stages.
Abstract:
Methods and systems for repurposing of a global navigation satellite system receiver for receiving low-earth orbit (LEO) communication satellite timing signals may comprise receiving medium Earth orbit (MEO) satellite signals and/or LEO signals in a receiver of the communication device. A radio frequency (RF) path may be configured to down-convert either of the signals, and a position of the communication device may be calculated utilizing the down-converted signals. The signals may be down-converted utilizing a local oscillator signal generated by a phase locked loop (PLL), which may be delta-sigma modulated via a fractional-N divider. A clock signal may be communicated to the PLL utilizing a temperature-compensated crystal oscillator. The signals may be down-converted to an intermediate frequency or down-converted directly to baseband frequencies. The signals may be processed utilizing surface acoustic wave (SAW) filters. In-phase and quadrature signals may be processed in the RF path utilizing a two-stage polyphase filter.