US 8,428,097 B2Granted

Power efficient software receiver for spread spectrum signals

AssigneeNordnav Technologies AB

InventorsPer-Ludvig Normark, Christian Ståhlberg

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Abstract

The present invention relates to reception and processing of spread spectrum signals to produce position/time related data. A proposed receiver includes a radio signal processing unit, which is at least partly implemented in software running on a microprocessor. The processor is also adapted to effect at least one separate software-controlled function. The receiver is adapted to operate the radio signal processing unit on at least two processing intensity levels each with different processing times. Thereby, when the radio signal processing unit operates on a low processing intensity level, a first amount of processing capacity is available for the at least one separate software-controlled function; and when the radio processing unit operates on a high processing intensity level, a second amount of processing capacity is available for the at least one separate software-controlled function. When the processor's over-all processing capacity is constant, the second amount is smaller than the first amount.

Claims25

Dependent claims

A spread spectrum signal receiver adapted to receive a number of radio signals, the receiver comprising:

a radio signal processing unit adapted to produce position/time related data in response to the received signals, the receiver being adapted to operate the radio signal processing unit on at least two processing intensity levels each at which an amount of processing per time unit is different, wherein the at least two processing intensity levels comprise a signal-source-acquisition level at which the radio signal processing unit is adapted to operate when searching for, identifying and synchronizing with at least one radio signal source, and wherein the radio signal processing unit is adapted to operate on the signal-source-acquisition level when generating a first estimate of the position/time related data;
wherein the radio signal processing unit is at least partly implemented in a software running on a microprocessor, the microprocessor is adapted to effect at least one separate software-controlled function in addition to the at least-part implementation of the radio signal processing unit, such that:
during periods when the radio signal processing unit operates on a relatively low processing intensity level, a first amount of processing capacity is available for the at least one separate software-controlled function, and
during periods when the radio processing unit operates on a relatively high processing intensity level, a second amount of processing capacity is available for the at least one separate software-controlled function, the second amount being smaller than the first amount;
wherein the receiver is further adapted to operate in at least two operation modes, and for each operation mode a unique operation scheme is defined according to which the processing performed by the radio signal processing unit is distributed over time between the at least two processing intensity levels;
and
a user interface adapted to receive user-initiated measurement control commands, the at least two operation modes further comprise:
a push-to-fix mode for which the operation scheme, after reception of a user-initiated measurement control command, defines:
an initial signal-source-acquisition level operation for the radio signal processing unit;
and
a subsequent tracking-level operation for the radio signal processing unit during at least a predefined measurement period.

8 more elements

A method of operating a spread spectrum signal receiver, the receiver being adapted to receive a number of radio signals and based thereon derive position/time related data, and a radio signal processing unit of the receiver being at least partly implemented in software running on a microprocessor which is adapted to effect at least one separate software-controlled function in addition to the at least-part implementation of the radio signal processing unit, the method comprising:

controlling the radio signal processing unit to operate on one of at least two processing intensity levels each at which an amount of processing per time unit is different;
adapting the radio signal processing unit to operate at a signal-source-acquisition level of the at least two processing intensity levels when searching for, identifying and synchronizing with at least one radio signal source;
rendering a first amount of processing capacity available for the at least one separate software-controlled function during periods when the radio signal processing unit operates on a relatively low processing intensity level, and a second amount of processing capacity available for the at least one separate software-controlled function during periods when the radio processing unit operates on a relatively high processing intensity level, the first amount being larger than the second amount;
and
controlling the receiver to operate in one of at least two operation modes, each mode being associated with a unique operation scheme which defines a distribution over time of the processing performed by the radio signal processing unit between the at least two processing intensity levels
wherein the at least two operation modes comprising a push-to-fix mode for which the operation scheme, after reception of a user-initiated measurement control command, comprises:
controlling the radio signal processing unit to operate on an initial signal-source-acquisition level;
and
controlling the radio signal processing unit to operate on a subsequent tracking-level during at least a predefined measurement period.

6 more elements

A computer program stored on a non-transitory computer readable medium and directly loadable into the internal memory of a computer for operating a spread spectrum signal receiver, the receiver being adapted to receive a number of radio signals and based thereon derive position/time related data, and a radio signal processing unit of the receiver being at least partly implemented in software running on a microprocessor which is adapted to effect at least one separate software-controlled function in addition to the at least-part implementation of the radio signal processing unit, said computer program comprising:

instructions for controlling the radio signal processing unit to operate on one of at least two processing intensity levels each at which an amount of processing per time unit is different;
instructions for adapting the radio signal processing unit to operate at a signal-source-acquisition level of the at least two processing intensity levels when searching for, identifying and synchronizing with at least one radio signal source;
instructions for rendering a first amount of processing capacity available for the at least one separate software-controlled function during periods when the radio signal processing unit operates on a relatively low processing intensity level, and a second amount of processing capacity available for the at least one separate software-controlled function during periods when the radio processing unit operates on a relatively high processing intensity level, the first amount being larger than the second amount;
and
instructions for controlling the receiver to operate in one of at least two operation modes, each mode being associated with a unique operation scheme which defines a distribution over time of the processing performed by the radio signal processing unit between the at least two processing intensity levels,
wherein the at least two operation modes comprising a push-to-fix mode for which the operation scheme, after reception of a user-initiated measurement control command, comprises:
instructions for controlling the radio signal processing unit to operate on an initial signal-source-acquisition level;
and
instructions for controlling the radio signal processing unit to operate on a subsequent tracking-level during at least a predefined measurement period.

6 more elements

A non-transitory computer readable medium, having a computer program recorded thereon for operating a spread spectrum signal receiver, the receiver being adapted to receive a number of radio signals and based thereon derive position/time related data and a radio signal processing unit of the receiver being at least partly implemented in software running on a microprocessor which is adapted to effect at least one separate software-controlled function in addition to the at least-part implementation of the radio signal processing unit, said computer program comprising:

instructions for controlling the radio signal processing unit to operate on one of at least two processing intensity levels each at which an amount of processing per time unit is different;
instructions for adapting the radio signal processing unit to operate at a signal-source-acquisition level of the at least two processing intensity levels when searching for, identifying and synchronizing with at least one radio signal source;
instructions for rendering a first amount of processing capacity available for the at least one separate software-controlled function during periods when the radio signal processing unit operates on a relatively low processing intensity level, and a second amount of processing capacity available for the at least one separate software-controlled function during periods when the radio processing unit operates on a relatively high processing intensity level, the first amount being larger than the second amount;
and
instructions for controlling the receiver to operate in one of at least two operation modes, each mode being associated with a unique operation scheme which defines a distribution over time of the processing performed by the radio signal processing unit between the at least two processing intensity levels,
wherein the at least two operation modes comprising a push-to-fix mode for which the operation scheme, after reception of a user-initiated measurement control command, comprises:
instructions for controlling the radio signal processing unit to operate on an initial signal-source-acquisition level;
and
instructions for controlling the radio signal processing unit to operate on a subsequent tracking-level during at least a predefined measurement period.

6 more elements

Dependencies are inferred from the claim text.