Method for detecting UWB pulse sequences without local pulse generation

• US 20050232381A1
• Filed: 03/18/2005
• Published: 10/20/2005
• Est. Priority Date: 03/22/2004
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Aubert, Louis-Marie, Paquelet, Stephane
• Granted Patent: US 7,551,891 B2
• Time in Patent Office: Days
• US Class Current: 375/343
• CPC Class Codes: H04B 1/71637 Receiver aspects H04B1/7183 takes precedence
• CPC Class Codes: H04B 1/7176 Data mapping, e.g. modulation

Abstract

The invention relates to a method for transmitting at least one sequence of Np pulses over Np time windows, each pulse being enclosed within a predetermined time chip Tc. The method according to the invention includes a signal detection step, in the course of which Np detection windows Dj (for j=1 to Np) encompassing predetermined time chips are examined by performing correlations over said detection windows Dj of the received signal with at least a first and a second sinusoidal signal S1 and S2. The method according to the invention enables to limit the processing time and power needed for carrying out the detection step, which only requires to examine detection windows defined by a signature of a transmitter by using sinusoidal signals, instead of mapping the whole pulse sequence by means of a correlation with expected pulses.

Claims

1. A method for transmitting data in a telecommunication system including at least one transmitter and one receiver, said transmitter being intended to transmit a signal formed by at least one sequence of Np pulses over Np time windows where Np is a predermined integer number, each pulse being enclosed within a time chip whose position whithin its relevant time window is defined by a chip number, which method includes at least one signal detection step to be executed by said receiver, in the course of which Np detection windows encompassing the time chips defined by the chip numbers are to be examined in search of an expected pulse sequence by performing at least a first and a second correlation over said detection windows of a signal representative of the received signal with at least a first and a second sinusoidal signal, respectively, which first and second sinusoidal signals are in phase quadrature with respect to each other, said first and second correlations being intended to produce first and second correlation values to be combined together into a single detection value intended to be compared to a predetermined threshold value.

2. A method according to claim 1, according to which the detection value is obtained by squaring each of the correlation values and adding together all resulting squared values.

3. A method as claimed in any one of claims 1 or 2, according to which the predetermined threshold value is independent of an amplitude of the received signal.

4. A telecommunication system including at least one transmitter and one receiver, said transmitter being intended to transmit a signal formed by at least one sequence of Np pulses over Np time windows, each pulse being enclosed within a time chip whose position whithin its relevant time window is defined by a chip number, system in which the receiver includes signal detection means intended to perform an examination of Np detection windows encompassing the time chips defined by the chip numbers in search of an expected pulse sequence, said detection means including at least first and second correlation means for correlating a signal representative of the received signal with at least a first and a second sinusoidal signal, respectively, which first and second sinusoidal signals are in phase quadrature with respect to each other, said first and second correlation means being intended to be activated during said detection windows and to produce first and second correlation values to be combined together into a single detection value intended to be fed to comparison means intended to compare said detection value with a predetermined threshold value.

5. A telecommunication system as claimed in claim 4, in which the detection means further include at least third and fourth correlation means for correlating a signal representative of the received signal with at least a third and a fourth sinusoidal signal, respectively, which third and fourth sinusoidal signals are in phase quadrature with respect to each other, said third and fourth correlation means being intended to be activated during said detection windows and to produce third and fourth correlation values to be combined together with the first and second correlation values into a single detection value intended to be fed to comparison means, the detection means also including a phase quadrature demodulator intended to be fed with the received signal and to respectively deliver a first and a second demodulated signal to the first and second correlation means, on the one hand, and to the third and fourth correlation means, on the other hand, which first and second demodulated signals are in phase quadrature with respect to each other.

6. A telecommunication system as claimed in claims 4 or 5, in which, the phase quadrature demodulator including two mixers intended to be fed with the received signal, on the one hand, and by demodulation signals in phase quadrature with each other having a so-called central frequency, the third and fourth sinusoidal signals being then respectively formed by the first and second sinusoidal signals, the detection means further include:

an oscillator intended to generate an output signal from which the first and second sinusoidal signals will be derived, and

a frequency multiplier intended to receive said output signal and to deliver respective first and second demodulation signals to the phase quadrature demodulator.

7. A telecommunication system as claimed in any one of claims 4 to 6, in which the detection means further include:

a plurality of accumulating modules, each of which being intended to accumulate output values delivered by one of said correlating means,

a plurality of squaring modules, each of which being intended to produce a squared value of the contents of one of said accumulating modules, and

an additioner intended to compute a sum of output values delivered by the squaring modules in order to produce the detection value to be compared to the predetermined threshold value.

8. A device intended to receive a signal formed by at least one sequence of Np pulses over Np time windows, each pulse being enclosed within a time chip whose position whithin its relevant time window is defined by a chip number, which receiver includes signal detection means intended to perform an examination of Np detection windows encompassing the time chips defined by the chip numbers in search of an expected pulse sequence, said detection means including at least first and second correlation means for correlating a signal representative of the received signal with at least a first and a second sinusoidal signal, respectively, which first and second sinusoidal signals are in phase quadrature with respect to each other, said first and second correlation means being intended to be activated during said detection windows and to produce first and second correlation values to be combined together into a single detection value intended to be fed to comparison means intended to compare said detection value with a predetermined threshold value.