Receiver for use in an ultra-wideband communication system
In an ultra-wideband (“UWB”) receiver, a received UWB signal is periodically digitized as a series of ternary samples. The samples are continuously correlated with a predetermined preamble sequence to develop a correlation value. When the value exceeds a predetermined threshold, indicating that the preamble sequence is being received, estimates of the channel impulse response (“CIR”) are developed. When a start-of-frame delimiter (“SFD”) is detected, the best CIR estimate is provided to a channel matched filter (“CMF”) substantially to filter channel-injected noise.
1. Apparatus for use in an ultra-wideband (UWB) communication system in which multi-symbol packets are transmitted via a transmission channel, each transmitted packet comprising a multi-symbol data payload, the apparatus comprising:
an analog-to-digital converter (ADC) adapted to:
receive a conditioned form of a received packet;
periodically sample said packet at a selected over-sample rate; and
provide corresponding samples, each sample comprising a selected one of:
a sign bit having a first value indicative of said sample being positive, and a second value indicative of said sample being negative; or
a single trit having a first value indicative of said sample being positive, a second value indicative of said sample being substantially zero, and a third value indicative of said sample being negative; or
a sign bit and a magnitude bit:
said sign bit having a first value indicative of said sample being positive, and a second value indicative of said sample being negative; and
said magnitude bit having a first value indicative of said sample being substantially zero, and a second value indicative of said sample being substantially non-zero; and
a digital channel matched filter adapted to receive a selected set of the samples, and to develop therefrom a multi-value result vector as a function of a best estimate of a channel impulse response (CIR) of said channel, the CIR estimate comprising a set of coefficients.
2. The apparatus of claim 1 wherein the channel matched filter further comprises:
a digital delay line adapted to:
serially receive the samples;
store a selected set of the received samples; and
provide the stored samples;
a digital CIR estimate store adapted to:
receive the coefficients comprising the CIR estimate;
store the received coefficients; and
provide the stored coefficients;
a digital multiplier adapted to:
receive the stored samples;
receive the stored coefficients; and
develop a set of partial sums, each as a function of a respective one of the stored samples and a respective one of the stored coefficients; and
a digital summer adapted to:
receive the partial sums; and
develop a respective one of the result vector values as a function of the received partial sums.
3. A receiver for use in an ultra-wideband (UWB) communication system in which multi-symbol packets are transmitted via a transmission channel, each transmitted packet comprising a multi-symbol data payload, the receiver comprising:
an analog-to-digital converter (ADC) adapted to:
receive a conditioned form of a received packet;
periodically sample said packet at a selected over-sample rate; and
provide corresponding samples, each sample comprising a selected one of:
a sign bit having a first value indicative of said sample being positive, and a second value indicative of said sample being negative; or
a single trit having a first value indicative of said sample being positive, a second value indicative of said sample being substantially zero, and a third value indicative of said sample being negative; or
a sign bit and a magnitude bit:
said sign bit having a first value indicative of said sample being positive, and a second value indicative of said sample being negative; and
said magnitude bit having a first value indicative of said sample being substantially zero, and a second value indicative of said sample being substantially non-zero; and
a digital channel matched filter adapted to receive a selected set of the samples, and to develop therefrom a multi-value result vector as a function of a best estimate of a channel impulse response (CIR) of said channel, the CIR estimate comprising a set of coefficients.
4. The apparatus of claim 3 wherein the channel matched filter further comprises:
a digital delay line adapted to:
serially receive the samples;
store a selected set of the received samples; and
provide the stored samples;
a digital CIR estimate store adapted to:
receive the coefficients comprising the CIR estimate;
store the received coefficients; and
provide the stored coefficients;
a digital multiplier adapted to:
receive the stored samples;
receive the stored coefficients; and
develop a set of partial sums, each as a function of a respective one of the stored samples and a respective one of the stored coefficients; and
a digital summer adapted to:
receive the partial sums; and
develop a respective one of the result vector values as a function of the received partial sums.
5. A method for operating an ultra-wideband (UWB) communication system in which multi-symbol packets are transmitted via a transmission channel, each transmitted packet comprising a multi-symbol data payload, the method comprising the steps of:
analog-to-digital converting each transmitted packet by:
receiving a conditioned form of a received packet;
periodically sampling said packet at a selected over-sample rate; and
providing corresponding samples, each sample comprising a selected one of:
a sign bit having a first value indicative of said sample being positive, and a second value indicative of said sample being negative; or
a single trit having a first value indicative of said sample being positive, a second value indicative of said sample being substantially zero, and a third value indicative of said sample being negative; or
a sign bit and a magnitude bit:
said sign bit having a first value indicative of said sample being positive, and a second value indicative of said sample being negative; and
said magnitude bit having a first value indicative of said sample being substantially zero, and a second value indicative of said sample being substantially non-zero; and
digitally channel match filtering a selected set of the samples, and developing therefrom a multi-value result vector as a function of a best estimate of a channel impulse response (CIR) of said channel, the CIR estimate comprising a set of coefficients.
6. The method of claim 5 wherein the method further comprises the steps of:
serially receiving the samples, storing a selected set of the received samples, and providing the stored samples;
receiving the coefficients comprising the CIR estimates, storing the received coefficients, and providing the stored coefficients;
receiving the stored samples and the stored coefficients, and developing a set of partial sums, each as a function of a respective one of the stored samples and a respective one of the stored coefficients; and
receiving the partial sums, and developing a respective one of the result vector values as a function of the received partial sums.