Pulse shaper design for ultra-wideband communications
First Claim
1. A method comprising generating digitally filtered ultra-wide band (UWB) pulses to substantially maximize power in one or more frequency bands of a UWB spectrum and to substantially reduce power in one or more narrow band interference (NBI) frequency bands of the UWB spectrum, wherein generating the digitally filtered UWB pulses comprises:
- generating a stream of information bearing symbols;
selecting spacing of a set of tap coefficients of a digital filter, the digital filter being included within a UWB transmitter;
selecting the set of tap coefficients based on the one or more frequency bands;
digitally filtering the stream of information bearing symbols according to the set of selected tap coefficients; and
generating, by the UWB transmitter, the digitally filtered UWB pulses based on the following equation;
where w[n] represents the nth tap coefficient, T0 represents the spacing of the coefficients, M represents the number of tap coefficients, g(t) represents analog pulse shaping, and p(t) represents the digitally filtered UWB pulses.
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Abstract
The invention provides an ultra-wideband (UWB) transmitter and various techniques for generating digitally filtered UWB pulses that substantially maximize power and bandwidth in one or more frequency bands while allowing narrow-band interference (NBI) to be avoided, e.g. interference to and from wireless local area networks (WLANs). In particular, the UWB transmitter utilizes a digital filter to generate digitally filtered UWB pulses to substantially maximize power and bandwidth in the Federal Communications Commission (FCC) spectral mask for UWB communications. In one embodiment, the invention provides a method comprising generating digitally filtered ultra-wide band (UWB) pulses to substantially maximize power in one or more frequency bands of a UWB spectrum and to substantially reduce power in one or more NBI frequency bands of the UWB spectrum. The invention may be implemented without modifying the analog components of existing UWB transmitters.
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Citations
53 Claims
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1. A method comprising generating digitally filtered ultra-wide band (UWB) pulses to substantially maximize power in one or more frequency bands of a UWB spectrum and to substantially reduce power in one or more narrow band interference (NBI) frequency bands of the UWB spectrum, wherein generating the digitally filtered UWB pulses comprises:
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generating a stream of information bearing symbols; selecting spacing of a set of tap coefficients of a digital filter, the digital filter being included within a UWB transmitter; selecting the set of tap coefficients based on the one or more frequency bands; digitally filtering the stream of information bearing symbols according to the set of selected tap coefficients; and generating, by the UWB transmitter, the digitally filtered UWB pulses based on the following equation; where w[n] represents the nth tap coefficient, T0 represents the spacing of the coefficients, M represents the number of tap coefficients, g(t) represents analog pulse shaping, and p(t) represents the digitally filtered UWB pulses. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
where {w0[n]}n=0L represents the set of tap coefficients, w0[n] represents the nth tap coefficient, e(F) represents an error function that approximates error between the one or more frequency bands and an approximation of the one or more frequency bands and is a function of the frequency of the UWB pulses F, and ζ
represents the union of disjoint intervals in the one or more frequency bands.
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6. The method of claim 1, wherein the one or more frequency bands of the UWB spectrum comprise at least one of frequency bands within a Federal Communications Commission (FCC) spectral mask for the UWB spectrum, a frequency sub-band of the UWB spectrum, and at least two frequency sub-bands of the UWB spectrum.
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7. The method of claim 1, wherein the one or more NBI frequency bands comprise a governmentally licensed frequency band within the UWB spectrum.
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8. The method of claim 1, wherein the one or more NBI frequency bands comprise at least one of a 5 GHz frequency band, a frequency band including wireless communications from wireless local area networks (WLAN), a frequency band having heavy traffic, and a frequency band including co-existing wireless communication systems.
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9. The method of claim 1, further comprising generating the digitally filtered UWB pulses according to a frequency hopping (FH) scheme, including substantially maximizing power of at least a portion of a given one of the pulses when the given one of the pulses falls within a selected FH frequency band and reducing the power of the given one of the pulses when the given one of the pulses falls outside the selected FH frequency band.
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10. The method of claim 1, wherein the digitally filtered UWB pulses substantially maximize power and bandwidth in a Federal Communications Commission (FCC) spectral mask for the UWB spectrum while reducing power in a 5 GHz frequency band.
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11. A digital filter of an ultra-wideband (UWB) transmitter that generates digitally filtered UWB pulses to substantially maximize power in one or more frequency bands of a UWB spectrum and to substantially reduce power in one or more narrow band interference (NBI) frequency bands of the UWB spectrum, wherein the digital filter generates the digitally filtered UWB pulses at least by:
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adaptively selecting a set of tap coefficients based on the one or more frequency bands; digitally filtering a stream of information bearing symbols according to the selected set of tap coefficients; and generating the digitally filtered UWB pulses based on the following equation; where w[n] represents a nth tap coefficient, T0 represents spacing of the coefficients, M represents a number of the tap coefficients, g(t) represents analog pulse shaping, and p(t) represents the digitally filtered UWB pulses. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. An ultra-wideband (UWB) transmitter comprising:
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a symbol generator that generates a stream of information bearing symbols; a digital filter that digitally filters the stream of information bearing symbols according to a set of tap coefficients to substantially maximize power in one or more frequency bands of a UWB spectrum and to substantially reduce power in one or more narrow band interference (NBI) frequency bands of the UWB spectrum, wherein the digital filter; selects spacing of the set of tap coefficients; selects the set of tap coefficients based on the one or more frequency bands; and digitally filters the stream of information bearing symbols according to the selected set of tap coefficients; a timer that processes the stream of information bearing symbols in accordance with a pulse position modulation (PPM) scheme; and a pulse generator that generates digitally filtered ultra-wideband (UWB) pulses based on the following equation; where w[n] represents an nth tap coefficient, T0 represents spacing of the coefficients, M represents a number of the tap coefficients, g(t) represents analog pulse shaping, and p(t) represents the digitally filtered UWB pulses. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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35. A method comprising digitally filtering ultrawide band (UWB) pulses to reduce power in one or more narrow band interference (NBI) frequency bands of a governmentally defined UWB spectrum, wherein digitally filtering the UWB pulses comprises:
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selecting spacing of a set of tap coefficients of a digital filter, the digital filter being included within a UWB transmitter; selecting the set of tap coefficients based on one or more frequency bands of the UWB spectrum; digitally filtering a stream of information bearing symbols according to the set of selected tap coefficients; and digitally filtering, by the UWB transmitter, the UWB pulses based on the following equation; where w[n] represents the nth tap coefficient, T0 represents the spacing of the coefficients, M represents the number of tap coefficients, g(t) represents analog pulse shaping, and p(t) represents the digitally filtered UWB pulses. - View Dependent Claims (36, 37, 38, 39, 40, 41)
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42. A digital filter of an ultrawide band (UWB) transmitter that digitally filters a plurality of UWB pulses to reduce power in one or more narrow band interference (NBI) frequency bands of a governmentally defined UWB spectrum, wherein the digital filter generates the digitally filtered UWB pulses at least by:
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adaptively selecting a set of tap coefficients based on one or more frequency bands of the UWB spectrum; digitally filtering a stream of information bearing symbols according to the selected set of tap coefficients; and generating the digitally filtered UWB pulses based on the following equation; where w[n] represents the nth tap coefficient, T0 represents the spacing of the coefficients, M represents the number of tap coefficients, g(t) represents analog pulse shaping, and p(t) represents the digitally filtered UWB pulses. - View Dependent Claims (43, 44, 45, 46, 47)
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48. An ultrawide band (UWB) transmitter including a digital filter that digitally filters a plurality of UWB pulses to reduce power in one or more narrow band interference (NBI) frequency bands of a governmentally defined UWB spectrum, wherein the digital filter:
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selects spacing of a set of tap coefficients; selects the set of tap coefficients based on one or more frequency bands of the UWB spectrum; and digitally filters a stream of information bearing symbols according to the selected set of tap coefficients, wherein the digital filter digitally filters the UWB pulses based on the following equation; where w[n] represents the nth tap coefficient, T0 represents the spacing of the coefficients, M represents the number of tap coefficients, g(t) represents analog pulse shaping, and p(t) represents the digitally filtered UWB pulses. - View Dependent Claims (49, 50, 51, 52, 53)
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Specification