FR2885751A1 - DEVICE AND METHOD FOR RADIO FREQUENCY RECEPTION OF BINARY DATA - Google Patents

Abstract

Device and method for radiofrequency reception of binary data in a radio frequency transmission channel, comprising capture means comprising an antenna and a main filter whose main bandwidth corresponds to said transmission channel and a correlation receiver, in which are implemented a frequency diversity receiver (3) comprising a parallel path multiplicity (VF1 to VFn) comprising respectively a secondary filter (Fs1) whose input is connected to the output of the main filter (Fp) and an envelope detection circuit and filtering adapted (Fa1) connected to the output of the secondary frequency filter and a summing circuit (7) whose input is connected to the outputs of said matching envelope detection and filter circuits and whose output is connected to the input of said correlation receiver (4). Said secondary filters have bandwidths corresponding to disjoint subbands included in said main bandwidth. Said envelope detection and filtering circuits adapted are adapted to detect pulses of determined shape in the signals from the secondary filters. Said summing circuit is adapted to add the signals from the envelope detection and filtering circuits adapted and delivering to said correlation receiver the resulting signal.

Description

Device and method for radiofrequency reception of binary data

  The present invention relates to the field of radio frequency pulsed transmission systems for binary data spread spectrum broadband (UWB).

  To illustrate a state of the art of this field, reference can be made to the document IEEE VOL.2.NO. 2, February 1998, pages 36 to 38.

  The object of the present invention is to further increase the safety and reliability of radio transmissions in the form of electromagnetic waves, in which a frequency diversity is implemented.

  The present invention may advantageously be connected to the emission device and the transmission method described in French patent application No. 0411459 filed on October 27, 2004.

  The present invention firstly relates to a radiofrequency device for receiving binary data in a radio frequency transmission channel, comprising capture means comprising an antenna and a main filter whose main bandwidth corresponds to said transmission channel and a receiver. correlation.

  According to the invention, the reception device further comprises, between the capturing means and the correlation receiver: a frequency diversity receiver comprising a multiplicity of parallel channels respectively comprising a secondary filter whose input is connected to the output of the main filter and a matching envelope and filter detection circuit connected to the output of the secondary frequency filter and a summing circuit whose input is connected to the outputs of said adapted envelope detection and filtering circuits and whose output is connected to the input of said correlation receiver.

  According to the invention, said secondary filters preferably have bandwidths corresponding to disjoint subbands included in said main bandwidth.

  According to the invention, said detection and filtering circuits are preferably adapted to detect pulses of a given shape in the signals coming from the secondary filters.

  According to the invention, said summation circuit is preferably adapted to add the signals from the circuits; envelope detection and filtering means and delivering a correlation receiver the resulting signal.

  According to the invention, said disjoint subbands are preferably adjacent.

  The present invention also relates to a radiofrequency reception method of expected binary data contained in a signal present in a radio frequency transmission channel.

  The method comprises: sensing the electromagmetic signals in a predefined main frequency band, dividing said main frequency band into disjoint frequency subbands, detecting a predetermined shape signal dan; each frequency subband, summing the detected signals, and despreading or demodulating the summed signal by applying a predefined random sequence and outputting a sDrtie signal.

  A particular embodiment of the present invention will now be described by way of nonlimiting example and illustrated by the drawing, in which: FIG. 1 represents an electronic diagram for a radiofrequency reception device according to the invention; FIG. 2 represents a principal impulsioanel signal superimposed on noise, originating from a transmission channel; FIG. 3 represents a spectrum of an impure ion contained in said main signal; - Figure 3a shows a pulse of said main signal; FIGS. 4, 5 and 6 show the secondary spectra of pulses of three secondary pulse signals; FIGS. 4a, 5a and 6a show pulses of said secondary pulse signals; FIGS. 4b, 5b and 6b show expected pulses derived from said secondary pulse signals; And FIG. 7 represents a summation pulse of the pulses of FIGS. 4b, 5b and 6b.

  Referring to FIG. 1, it can be seen that a binary signal reception device 1 has been represented, which comprises in series a capture circuit 2, a frequency diversity receiver 3 and a correlation receiver 4.

  The capture circuit 2 comprises in series an antenna 5, a main frequency filter Fp main bandwidth and an amplifier 6, for example low gain connected to a point J. The frequency diversity receiver 3 comp: end, between the point J and a point K, a number of parallel channels VF1 to VFn and a summation circuit 7 in series.

  The channels VF1 to VFn, respectively mounted between the point J and the inputs of the summing circuit 7, respectively comprise, in series, secondary frequency filters Fs1 to Fsn, amplifiers Al to An, preferably at large gains, and circuits envelope detection and filtering adapted Fal to Fan.

  The correlation receiver 4, known per se, comprises in series, between the output K of the summing circuit 7 and a final output L of a binary signal, a multiplier circuit 8, an integration circuit 9 and a decision circuit 10, and comprises a despreading sequence generating circuit 11 connected to the integration circuit 9 and a synchronization circuit 12 connected to the despreading sequence generating circuit 11 and to the points K and L. The receiving device 1 is adapted to receive, to detect and delivering, at its output L, binary signals of origin Bi transported by electromagnetic waves, originating from a transmission device generating a spectral spreading of the signal according to a random sequence PN and a frequency diversity, for example originating from a device emission described in the French patent application number 0411459 filed October 27, 2004.

  We will now describe how the receiver device 1, assuming that it will deliver at its output L an expected binary signal Bi slots.

  By way of example, it will be assumed that the original binary signal Bi is transported by a radio wave in respectively three adjacent frequency sub-bands: BPs1, BPs2 and BPs3 of a main bandwidth BPp, in the form of pulses spaced from a pulse signal, with corresponding spectral spreads in each subband according to a random sequence PN. It will further be assumed that the aforementioned radio wave is not disturbed by another signal.

  The capture circuit 2 captures the airwave and delivers at its output J, through its main filter Fp, the main pulse signal Spf contained in a main band of frequencies.

  In FIG. 2, there is shown in part a main pulse signal Spf, which comprises spaced pulses on which is superimposed a noise coming from the transmission channel and generated by the components of the capture circuit.

  In FIG. 3, the spectrum of a pulse among the pulses of an expected pulse signal Spf occupying a main bandwidth BPp of frequencies of between 3.1 gigahertz and 10.6 gigahertz constituting a determined transmission channel is shown in limiting manner. . This main bandwidth BPp is identical to the transmission frequency band of the aforementioned emission device.

  FIG. 3a is a limiting representation of one of the pulses constituting the expected signal Spf.

  The secondary filters Fs1 to Fsn of the frequency-diversity receiver 3 determine disjoint sub-bands, included in the aforementioned main bandwidth of the main frequency fi le Fp.

  The secondary filters Fs1 to Fsn receive: or the main pulse signal Spf via the point J and delivers at their output only the secondary pulse signals Ssfl to Ssfn contained in the corresponding subbands.

  FIGS. 4, 5 and 6 show, as an example, in decomposition of the spectrum of FIG. 3, the secondary spectra respectively of a pulse of three secondary pulse signals Ssf1, Ssf2 and Ssf3 contained in three sub-bandwidths of disjoint and adjacent frequencies BPs1, BPs2 and BPs3. These three sub-bands are advantageously between 3.1 gigahertz and 5.6 gigahertz, between 5.6 gigahertz and 8.1 gigahertz and between 8.1 gigahertz and 10.6 gigahertz, leaving three secondary filters Fsl, Fs2 and Fs3 of a 3-way VF1, VF2 and VF3 frequency diversity receiver. The three subbands BPs1, BPs2 and BPs3 are identical to the three transmission subbands of the aforementioned transmission device.

  FIGS. 4a, 5a and 6a respectively show, in decomposition of the pulse of FIG. 3a, one form of a pulse among the pulses constituting the secondary pulse signals Ssf1, Ssf2 and Ssf3.

  The detection and filtering circuits adapted to the Fan are capable of delivering pulses successions P1 to Pn when they receive secondary filters Fs1 to Fsn, via the amplifiers A1 to An, pulses whose shape corresponds to a form expected or approximately to such an expected form, i.e. the expected pulses of secondary pulse signals Ssfl to Ssfn.

  The detection and filtering circuits adapted to Fan Fal can contain for example a series energy detector with an envelope detection circuit and filtering adapted to the shape of the envelope of expected pulses.

  FIGS. 4b, 5b and 6b respectively show, in correspondence with FIGS. 4a, 5a and 6a, the shape of a pulse of the expected pulse successions P1, P2 and P3 coming out of the three detection circuits of FIG. adapted envelope and filter Fal, Fa2 and Fa3 of the three channels VF1, VF2 and VF3 above.

  The successions of expected pulses P1 to Pn, for example the successions of pulses P1, P2 and P3, are identical and correspond temporally.

  The summation circuit 7 receives the expected pulse successions P1 to P1 and delivers at its output a signal SOM corresponding to the addition of the pulse successions P1 to Pn.

  FIG. 7 is an example of the shape of a pulse SOM of a signal SOM corresponding to the addition of three corresponding pulses coming from the three adapted envelope detection and filtering circuits Fal, Fa2 and Fa3 of three channels VF1, VF2 and VF3 above.

  The operation of the correlation receiver 4 is known per se and is in particular described in the document IEEE VOL. COM-25, NO.8, August 1977, pages 748-755 and the IEEE VOL. COM-30, NO.5, May 1982, pages 855-884.

  Thus, the correlation receiver 4 performs a despreading of the expected signal SOM by applying the preprogrammed PN random sequence of the despreading sequence generating circuit 11 so as to reconstruct an expected output binary signal Bs on the output L. This sequence pre-programmed random number PN corresponds to the random sequence that led to the spread generated in the associated transmission device. The synchronization circuit 12 is adapted so that the PN sequence generated by the despreading sequence generator circuit 11 is synchronous and in phase with the PN sequence used by the associated transmission device.

  Since the pre-set electromagnetic wave is not seriously disturbed, this output signal Bs corresponds to the expected binary signal Bi.

  The reception device 1 which has just been written has the advantage of increasing the security of reception and detection of an expected binary signal.

  If in fact one of the aforementioned frequency sub-bands of the transmission channel is disturbed, the expected binary signal can nevertheless be delivered due to the accumulation or addition made in the summation circuit 7 of the signals from the sub-frequencies. undisturbed frequency bands.

  Another advantage of the receiving device 1 lies in the fact that it makes it possible to detect and deliver the expected signal Bi even in the case where the signal received by its antenna is embedded in a noise of relatively high level as represented by an example. in Figure 2.

  The present invention is not limited to the particular embodiments described above. Many variations are possible without departing from the scope defined by the appended claims.

Claims (3)

  1. Device for radiofrequency reception of binary data in a transmission radiofrequency channel, comprising capture means comprising an antenna and a main filter whose main bandwidth corresponds to said transmission channel and a correlation receiver, characterized in that it further comprises, between the capturing means (2) and the correlation receiver (3): a frequency diversity receiver (3) comprising a multiplicity of parallel channels (VF1 to VFn) respectively comprising a secondary filter (Fs1) whose the input is connected to the output of the main filter (Fp) and an adapted filter and filter circuit (Fal) connected to the output of the secondary frequency filter and a summation circuit (7) whose inputs are connected at the outputs of said appropriate envelope detection and filtering circuits and whose output is connected to the input of said correlation receiver (4); said secondary filters having bandwidths corresponding to disjoint subbands included in said main bandwidth, said adapted envelope and filter detection circuits being adapted to detect pulses of a given shape in the signals from the secondary filters, and said summing circuit being adapted to i.dndition the signals from the appropriate envelope detection and filtering circuits and delivering the resulting signal to said correlation receiver.   2. Device according to claim 1, characterized in that said disjoined subbands are adjacent.   A method of radiofrequency reception of expected binary data contained in a signal present in a radio frequency transmission channel, comprising sensing the electromagmetic signals of a predefined main frequency band, dividing said main frequency band into disjoint frequency subbands, Detecting a predetermined shape signal dan ;; each frequency subband, summing the detected signals, and despreading or demodulating the summed signal by applying a predefined random sequence and outputting an output signal.