Abstract: A communications device, such as a GNSS receiver comprises an oscillator, having a temperature-dependent frequency characteristic, for generating signals at a nominal frequency; receiver circuitry, for receiving transmitted wireless signals using the signals generated by the oscillator; at least one temperature sensor, having a known positional relationship to the oscillator; an estimation device, for estimating a frequency of the signals generated by the oscillator, based on a measurement from the temperature sensor, and based on the temperature-dependent frequency characteristic of the oscillator; and at least one heat source. A change in the temperature of the oscillator is predicted, based on a state of the heat source, and further based on a model of the thermal properties of the communications device, and hence a change in the frequency of the signals generated by the oscillator is predicted, based on the temperature-dependent frequency characteristic of the oscillator.

Abstract: The present invention provides a system for detecting timing characteristics of internal signals in a communications device, the system comprising: a system clock running at a known frequency; a test counter having a test input at which an internal signal to be tested is received; a gating counter having an input arranged to receive the system clock signal; and a system controller for controlling the counters; wherein the system controller controls the gating counter to count a predetermined number of system clock cycles to define a test period, and during the test period the test counter counts the cycles of the internal signal under test, whereby timing characteristics of the internal signal may be found with reference to a time base defined by the system clock. An associated method of operation is also described.

Abstract: A communications device, such as a GNSS receiver comprises an oscillator, having a temperature-dependent frequency characteristic, for generating signals at a nominal frequency; receiver circuitry, for receiving transmitted wireless signals using the signals generated by the oscillator; at least one temperature sensor, having a known positional relationship to the oscillator; an estimation device, for estimating a frequency of the signals generated by the oscillator, based on a measurement from the temperature sensor, and based on the temperature-dependent frequency characteristic of the oscillator; and at least one heat source. A change in the temperature of the oscillator is predicted, based on a state of the heat source, and further based on a model of the thermal properties of the communications device, and hence a change in the frequency of the signals generated by the oscillator is predicted, based on the temperature-dependent frequency characteristic of the oscillator.

Abstract: The present invention provides a system for detecting timing characteristics of internal signals in a communications device, the system comprising: a system clock running at a known frequency; a test counter having a test input at which an internal signal to be tested is received; a gating counter having an input arranged to receive the system clock signal; and a system controller for controlling the counters; wherein the system controller controls the gating counter to count a predetermined number of system clock cycles to define a test period, and during the test period the test counter counts the cycles of the internal signal under test, whereby timing characteristics of the internal signal may be found with reference to a time base defined by the system clock. An associated method of operation is also described.