Wireless data communication method via ultra-wide band encoded data signals, and receiver device for implementing the same

• US 7,848,456 B2
• Filed: 12/21/2004
• Issued: 12/07/2010
• Est. Priority Date: 01/08/2004
• Status: Expired due to Fees

• Current Assignee: Ecole polytechnique fãdãrale de lausanne epfl (Schweizerische Eidgenossenschaft)
• Original Assignee: Institut De Microtechnique Universite De Neuchatel
• Inventors: Farine, Pierre-Andre, Botteron, Cyril, Merz, Roman
• Primary Examiner(s): Fan; Chieh M
• Assistant Examiner(s): Garcia; Santiago
• Application Number:
  US10/597,067
• Publication Number:
  US 20070147476A1
• Time in Patent Office: 2,177 Days
• Field of Search: 375/260, 375/159, 375/130
• US Class Current: 375/310
• CPC Class Codes: H04B 1/71632 Signal aspects H04B1/7172 and H04B1/7176 take precedence
• CPC Class Codes: H04B 1/71635 Transmitter aspects H04B1/7174 takes precedence
• CPC Class Codes: H04B 1/7183 Synchronisation

Abstract

This invention concerns a wireless data communication method, wherein a transmitter device having a first wide band antenna transmits ultra-wide band coded data signals to a receiver device having a second wide band antenna for receiving the direct and/or multiple path coded data signals. The transmitted data is defined by one or several sequences of N pulses where N is an integer number greater than 1. The arrangement of the N pulses of each sequence represents a data coding relative to the transmitter device. The N pulses of a sequence of direct and/or multiple path coded data signals received by the receiver device are processed each in one among N corresponding reception time windows. Each of the N reception time windows is positioned in time based on a known theoretic arrangement of the N pulses of signals transmitted by the transmitter device. An adding operation of the N windows is then performed in the receiver device so that the amplitude level of the constantly added pulses is higher than the amplitude level of the noise sensed by the receiver device.

Claims

1. A wireless data communication method between a transmitter device having a first wide band antenna for transmitting ultra wide band coded data signals, and a receiver device having a second wide band antenna for receiving direct path and multiple path coded data signals, wherein the method comprises the steps of:

(a) defining transmitted data by one or more sequences of N pulses where N is an integer number higher than 1, wherein the arrangement of N pulses of each sequence represents encoding of data relating to the transmitter device;

(b) the receiver device receiving the N pulses of one pulse sequence of direct path and multiple path coded data signals, wherein the N pulses are each processed in one of N corresponding reception time windows, wherein each of the N reception time windows is positioned in time as a function of a known theoretical arrangement of the N pulses of the signals transmitted by the transmitter device; and

(c) carrying out, in the receiver device, an operation of adding the N windows in a coherent manner before data demodulation so that added pulse amplitude level is higher than noise amplitude level captured by the receiver device;

(d) performing an operation of adding the N time windows before or after analogue-digital conversion of the analogue signals, and wherein the analogue signal pulses are sampled in the analogue-digital conversion stage by at least one sampling signal supplied by a signal processing unit, wherein the sampling signal has a frequency proportional to a frequency of a clock signal; and

(e) calculating several absolute value maximum amplitude values for signals in time sub-windows of defined length T_N, wherein each of the sub-windows is time shifted in relation to each other by a determined time interval from the start of the reception time window to the end of said time window.

2. A wireless data communication method according to claim 1, wherein a first clock signal frequency for clocking various operations of the receiver device is proportionally adapted to a reference clock signal frequency of the transmitter device by controlling the pulse amplitude level of a final window adding the N windows until said amplitude level is maximised, wherein the reference clock signal frequency is used to generate ultra-wide band coded data signals.

3. A wireless data communication method according to claim 1, wherein the transmitter device transmits coded data signals, in which the data is coded by pulse position modulation of each sequence, or by pulse polarity or by phase modulation of each sequence, or by pulse position and polarity modulation of each sequence.

4. A wireless data communication method according to claim 1, wherein the coded data signals include a synchronisation frame allowing the receiver device to recognise the transmitter device and to be synchronised on said frame before demodulating the received data, wherein said synchronisation frame is composed of one or several sequences of N pulses of determined pulse repetition frequency.

5. A wireless data communication method according to claim 1, wherein the identical width of each of the N time windows is smaller than the reverse of the mean pulse repetition frequency of a sequence of coded data signals to be transmitted, and wherein said time window width is adapted to receive the pulses of the direct path and multiple path signals captured by the receiver device of width greater than 20 ns.

6. A wireless data communication method according to claim 1, wherein the time window signals are successively added and stored in at least one register of the signal processing unit.

7. A wireless data communication method according to claim 2, wherein each reception window, positioned in time in relation to the known theoretical arrangement of each pulse of the received data signals, is centered relative to a theoretical reference value or relative to the maximum added pulse amplitude of the direct path signals and multiple path signals captured by the receiver device.

8. A wireless data communication method according to claim 3, wherein the reference signals of identical polarity to the polarity of the coded signals received by the receiver device are correlated prior to addition of the resulting pulses of each time window.

9. A wireless data communication method according to claim 1, wherein the second signal processing unit includes means for adding the digital windows and means for estimating the time of arrival of the coded data signals, wherein before or after the time window addition operation is performed, the method further includes the steps of:

(f) estimating a noise amplitude level by selecting the minimum amplitude value from all the calculated amplitude values.

10. A wireless data communication method according to claim 1, wherein the method further includes the following steps:

(f) calculating a positive envelope of the signals of one time window by

i. determining all the zero crossing positions p_i of the time window signals;

ii. determining the coordinates of the absolute value amplitude maximum in each interval from p_i to p_i+1, with i ranging from 1 to I−

1, wherein I is an integer number higher than 3; and

iii. calculating the positive envelope by using a specific interpolation algorithm passing through the determined coordinates.

11. A wireless data communication method according to claim 10, wherein the method further includes the following steps:

(g) calculating the time of arrival of the first signals captured by the receiver device by

i. calculating an amplitude threshold th based on the amplitude maximum of the envelope and an estimated noise amplitude level;

ii. estimating the rising edge of the positive envelope where the threshold th is exceeded for the first time;

iii. estimating the maximum local point of the positive envelope at the coordinates that directly follow the point where the positive envelope passes above the threshold th, and the minimum local point of the envelope at the coordinates that precede the point where the positive envelope passes above the threshold th;

iv. calculating the intermediate coordinates between the minimum point and the maximum point;

v. approximating at the position of intermediate coordinates a selected segment of samples of the positive envelope with a given function; and

vi. determining the time of arrival of the first signals captured by the receiver device at the zero crossing or another value of the determined function.

12. A wireless data communication method according to claim 1, wherein the second signal processing unit includes control means for providing control signals to digital window addition means in order to modify the time or mean repetition frequency scale of N windows to be added from digital window addition means, wherein a re-sampling operation is carried out in the signal processing unit of the receiver device with a different re-sampling frequency from the sampling frequency of the analogue-digital conversion stage, wherein said re-sampling frequency generated by the control means is higher than the sampling frequency in order to increase precision for positioning purposes.

13. A receiver device for implementing the wireless data communication method according to claim 1, wherein the receiver device has a second wide band antenna for receiving direct path and multiple path coded data signals from a transmitter device, wherein the receiver device includes

i. an oscillator stage delivering at least one clock signal at a defined frequency;

ii. a signal processing unit connected to the oscillator stage;

iii. an analogue-digital conversion stage for analogue signals relating to the coded data signals received by the second wide band antenna, wherein the signal processing unit includes time window addition means for coherently adding up the pulses of each of the N time windows before or after analogue-digital conversion of the analogue signals; and

iv. demodulation means for demodulating data from digital signals after the time window addition means,

wherein the analogue-digital conversion stage operates to sample the analogue signal pulses by at least one sampling signal supplied by the signal processing unit, wherein said sampling signal has a frequency proportional to the clock signal frequency of the receiver device.

14. A receiver device according to claim 13, wherein the clock signal frequency of the oscillator stage is proportionally adapted by the processing unit to a reference clock signal frequency of an oscillator stage of the transmitter device by controlling the pulse amplitude level of a final addition window of the N windows from the addition means until said amplitude level is maximised, wherein the oscillator stage is used to generate ultra-wide band coded data signals.

15. A receiver device according to claim 13, wherein the time window addition means receive digital signals from the analogue-digital conversion stage for adding up the digital windows.

16. A receiver device according to claim 13, wherein the time window addition means receive analogue data signals from the second wide band antenna in order to add up the analogue windows.

17. A wireless data communication method according to claim 11, wherein the given function is an affine function.

18. A wireless data communication method between a transmitter device having a first wide band antenna for transmitting ultra wide band coded data signals, and a receiver device having a second wide band antenna for receiving direct path and multiple path coded data signals, wherein the method comprises the steps of:

(a) defining transmitted data by one or more sequences of N pulses where N is an integer number higher than 1, wherein the arrangement of N pulses of each sequence represents encoding of data relating to the transmitter device;

(b) the receiver device receiving the N pulses of one pulse sequence of direct path and multiple path coded data signals, wherein the N pulses are each processed in one of N corresponding reception time windows, wherein each of the N reception time windows is positioned in time as a function of a known theoretical arrangement of the N pulses of the signals transmitted by the transmitter device; and

(c) carrying out, in the receiver device, an operation of adding the N windows so that added pulse amplitude level is higher than noise amplitude level captured by the receiver device, wherein the receiver device further comprises a second signal processing unit that includes means for adding the digital windows and means for estimating the time of arrival of the coded data signals, wherein before or after the time window addition operation is carried out, the method further includes the steps of

(d) calculating several absolute value maximum amplitude values for signals in time sub-windows of defined length T_N, wherein each of the sub-windows is time shifted in relation to each other by a determined time interval from the start of the reception time window to the end of said time window; and

(e) estimating a noise amplitude level by selecting the minimum amplitude value from all the calculated amplitude values.

19. A wireless data communication method between a transmitter device having a first wide band antenna for transmitting ultra wide band coded data signals, and a receiver device having a second wide band antenna for receiving direct path and multiple path coded data signals, wherein the method comprises the steps of:

(a) defining transmitted data by one or more sequences of N pulses where N is an integer number higher than 1, wherein the arrangement of N pulses of each sequence represents encoding of data relating to the transmitter device;

(b) the receiver device receiving the N pulses of one pulse sequence of direct path and multiple path coded data signals, wherein the N pulses are each processed in one of N corresponding reception time windows, wherein each of the N reception time windows is positioned in time as a function of a known theoretical arrangement of the N pulses of the signals transmitted by the transmitter device; and

(c) carrying out, in the receiver device, an operation of adding the N windows in a coherent manner before data demodulation so that added pulse amplitude level is higher than noise amplitude level captured by the receiver device, wherein the transmitter device includes

i. a first oscillator stage delivering at least one first clock signal at a first defined frequency;

ii. a first signal processing unit clocked by the clock signal provided by the first oscillator stage in order to modulate the data to be transmitted; and

iii. a unit for shaping the N pulses of each sequence to be transmitted by the first wide band antenna of the transmitter device as a function of the data modulation provided by the first signal processing unit; and

wherein the receiver device includes

i. a second oscillator stage delivering at least one second clock signal at a second defined frequency;

ii. a second signal processing unit connected to the second oscillator stage; and

iii. an analogue-digital conversion stage for analogue signals relating to the coded data signals received by the second wide band antenna; and

(d) calculating several absolute value maximum amplitude values for signals in time sub-windows or defined length T_N, wherein each of the sub-windows is time shifted in relation to each other by a determined time interval from the start of the reception time window to the end of said time window.

20. A wireless data communication method between a transmitter device having a first wide band antenna for transmitting ultra wide band coded data signals, and a receiver device having a second wide band antenna for receiving direct path and multiple path coded data signals, wherein the method comprises the steps of:

(a) defining transmitted data by one or more sequences of N pulses where N is an integer number higher than 1, wherein the arrangement of N pulses of each sequence represents encoding of data relating to the transmitter device;

(b) the receiver device receiving the N pulses of one pulse sequence of direct path and multiple path coded data signals, wherein the N pulses are each processed in one of N corresponding reception time windows, wherein each of the N reception time windows is positioned in time as a function of a known theoretical arrangement of the N pulses of the signals transmitted by the transmitter device; and

(c) carrying out, in the receiver device, an operation of adding the N windows in a coherent manner before data demodulation so that added pulse amplitude level is higher than noise amplitude level captured by the receiver device,

wherein the transmitter device includes

i. a first oscillator stage delivering at least one first clock signal at a first defined frequency;

ii. a first signal processing unit clocked by the clock signal provided by the first oscillator stage in order to modulate the data to be transmitted; and

iii. a unit for shaping the N pulses of each sequence to be transmitted by the first wide band antenna of the transmitter device as a function of the data modulation provided by the first signal processing unit; and

wherein the receiver device includes

i. a second oscillator stage delivering at least one second clock signal at a second defined frequency;

ii. a second signal processing unit connected to the second oscillator stage; and

iii. an analogue-digital conversion stage for analogue signals relating to the coded data signals received by the second wide band antenna, wherein

the method further comprises the steps of;

(d) performing an operation of adding the N time windows before or after analogue-digital conversion of the analogue signals, and wherein the analogue signal pulses are sampled in the analogue-digital conversion stage by at least one sampling signal supplied by the second signal processing unit, wherein the sampling signal has a frequency proportional to the second frequency of the second clock signal; and

(e) calculating several absolute value maximum amplitude values for signals in time sub-windows of defined length T_N, wherein each of the sub-windows is time shifted in relation to each other by a determined time interval from the start of the reception time window to the end of said time window.