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US 6,647,054 B1Granted
Multiple mask arrangement for jumping in pseudo-noise sequences
AssigneeKoninklijke Philips Electronics N.V.
InventorDaniel J. Greenhoe
Life of this patent
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Abstract
Multiple masks are applied in a selected combination to a pseudo-noise sequence (PNS) output from a linear feedback shift register to shift the position of the PNS by a desired amount. Each mask shifts the PNS by a power of 2 and the selected combination of masks adds these shifts to provide the selected shift. The desired bit length of the shift in binary form is directly mapped to a combination of masks to apply the correct masking to the PNS.
Claims18
A pseudo-noise sequence (PNS) generator comprising:
- a linear feedback shift register (LFSR) for producing a PNS at an output;
- a plurality of LFSR masks each having a mask input and a mask output, the mask input having a version of the PNS and the mask output providing a shifted version of the PNS with respect to the version of the PNS provided to the mask input, the LFSR masks forming a series of previous and subsequent LFSR masks;
- a plurality of registers within each of the masks arranged to form a binary shift register, each register a having a register input and a register output sequentially connecting the registers, the registers being operatively configured such that bits defining the version of the PNS will be shifted from a first register to a last register;
- a series a switches within each of the LFSR masks operatively connected to receive the register outputs, each of the switches having a switch input and a switch output;
- and
- a series of adders within each of the LFSR masks, each of the adders having at least a first input, a second input and a single output, and wherein the switches selectively controls the adders to operate on the first input and the second input or to pass the second input to the single output, wherein either the version of the PNS or the shifted version of the PNS is output by the series of adders;
- wherein the mask input of a first LFSR mask in the LFSR mask series is connected to the output of the LFSR, the mask input of each subsequent LFSR mask in the LFSR series is connected to the single output of the switch of the previous LFSR mask, the single output of the respective switch for a last LFSR mask in the series of LFSR masks, provides a PNS generator output.
4 more elements
A transmitter comprising:
- an input for an information signal;
- a power supply;
- a microcontroller connected to the power supply;
- a linear feedback shift register (LFSR) for producing a PNS at an output;
- a plurality of LFSR masks each having a mask input and a mask output, the mask input having a version of the PNS and the mask output providing a shifted version of the PNS with respect to the version of the PNS provided to the mask input, the LFSR masks forming a series of previous and subsequent LFSR masks;
- a plurality of registers within each of the masks arranged to form a binary shift register, each register a having a register input and a register output sequentially connecting the registers, the registers being operatively configured such that bits defining the version of the PNS will be shifted from a first register to a last register;
- a series a switches within each of the LFSR masks operatively connected to receive the register outputs, each of the switches having a switch input and a switch output;
- and
- a series of adders within each of the LFSR masks, each of the adders having at least a first input, a second input and a single output, and wherein the switches selectively controls the adders to operate on the first input and the second input or to pass the second input to the single output, wherein either the version of the PNS or the shifted version of the PNS is output by the series of adders;
- wherein the mask input of a first LFSR mask in the LFSR mask series is connected to the output of the LFSR, the mask input of each subsequent LFSR mask in the LFSR series is connected to the single output of the switch of the previous LFSR mask;
- a spreader to spread the information signal depending on the output of the switch for a last LFSR mask in the series of LFSR masks;
- and
- transmitter apparatus for transmitting the spread information signal into a medium.
10 more elements
A transmitter comprising:
- receiver means for receiving a spread information signal from a medium;
- a power supply;
- a microcontroller connected to the power supply;
- a linear feedback shift register (LFSR) for producing a PNS at an output;
- a plurality of LFSR masks each having a mask input and a mask output, the mask input having a version of the PNS and the mask output providing a shifted version of the PNS with respect to the version of the PNS provided to the mask input, the LFSR masks forming a series of previous and subsequent LFSR masks;
- a plurality of registers within each of the masks arranged to form a binary shift register, each register a having a register input and a register output sequentially connecting the registers, the registers being operatively configured such that bits defining the version of the PNS will be shifted from a first register to a last register;
- a series a switches within each of the LFSR masks operatively connected to receive the register outputs, each of the switches having a switch input and a switch output;
- and
- a series of adders within each of the LFSR masks, each of the adders having at least a first input, a second input and a single output, and wherein the switches selectively controls the adders to operate on the first input and the second input or to pass the second input to the single output, wherein either the version of the PNS or the shifted version of the PNS is output by the series of adders;
- wherein the mask input of a first LFSR mask in the LFSR mask series is connected to the output of the LFSR, the mask input of each subsequent LFSR mask in the LFSR series is connected to the single output of the switch of the previous LFSR mask, the output of the switch for a last LFSR mask in the series of LFSR masks, provides a PNS generator output;
- a de-spreader to de-spread the spread information signal depending on the PNS generator output to produce a recovered information signal;
- and
- an output for the recovered information signal.
10 more elements
A method of operating a recursive system, with an output depending on a plurality of previous outputs comprising the steps of:
- processing the plurality of previous outputs from a linear feedback shift register to obtain processed values;
- storing the processed values within a mask;
- determining new outputs within the mask depending on the processed values;
- and
- reverse processing the processed values within the mask to obtain the previous outputs.
2 more elements
Dependencies are inferred from the claim text.