EP1880488A1

EP1880488A1 - Device and method for receiving binary data radio frequency

Info

Publication number: EP1880488A1
Application number: EP06764588A
Authority: EP
Inventors: Emil Novakov; Stanislas Voinot; Jean-Michel Fournier
Original assignee: Stantec SA
Current assignee: Stantec SA
Priority date: 2005-05-10
Filing date: 2006-05-03
Publication date: 2008-01-23
Also published as: FR2885751B1; WO2006120319A1; FR2885751A1

Abstract

The invention relates to a device and method for receiving binary data radio frequency in a radio frequency transmitting channel, wherein the inventive device comprises pick-up means provided with an antenna and a main filter, whose main band-pass corresponds to said transmitting channel, and a correlation receiver, in which a frequency diversity receiver (3) comprising a plurality of parallel channels (VF1 to VFn) is used, wherein each channel is provided with a secondary filter (Fs1), respectively, whose input is connected to the main filter (Fp) output, matched envelop detection and filtering (Fa1) circuits connected to a secondary filter output and a summing circuit (7) whose input is connected to the outputs of said envelop detection and matched filtering circuits and output is connected to the input of said correlation receiver (4). The band-pass of said secondary filters correspond to disjointed sub-bands included into said main band-pass. The matched envelop detection and filtering circuits are used for detecting desired-shape pulses in signals received from the secondary filters. The summing circuit is used for adding the signal received form the matched envelop detection and filtering circuits and for transmitting a resulting signal to the correlation receiver.

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 purpose 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 transmission device and the transmission method described in the French patent application number 041 1459 filed October 27, 2004.

The present invention is firstly obj and a device 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.

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 and filter detection 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 summing circuit is preferably adapted to add the signals from the envelope detection and filtering circuits adapted and delivering to said correlation receiver the resulting signal.

According to the invention, said disjoint subbands are preferably adj acentes.

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.

This method comprises: sensing the electromagetic signals in a predefined main frequency band, dividing said main frequency band into disjoint frequency subbands, detecting a predetermined shape signal in 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.

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 of a radiofrequency reception device according to the invention;

FIG. 2 represents a main impulse signal superimposed on noise, originating from a transmission channel;

FIG. 3 represents a spectrum of a pulse 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 summing tap of the taps 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 comprises, between the point J and a point K, a number of parallel channels VF1 to VFn and in series a summation circuit 7. The channels VF1 to VFn, respectively mounted between the point J and the inputs of the summation circuit 7, respectively comprise, in series, secondary frequency filters Fs I to Fsn, amplifiers A1 to An, preferably at large gains, and adapted envelope detection and filtering circuits FaI 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 generator circuit 1 1 connected to the integration circuit 9 and a synchronization circuit 12 connected to the despreading sequence generating circuit 1 1 and to the points K and L.

The reception device 1 is adapted to receive, detect and deliver at its output L binary signals of origin Bi carried by electromagnetic waves, originating from a transmission device generating a spectral spread of the signal according to a random sequence PN and a frequency diversity, for example from a transmission device described in the French patent application number 041 1459 filed October 27, 2004. We will now describe how the device works 1, assuming that it will deliver at its output L an expected binary signal Bi with 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 BPs I, 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 in a PN random sequence. 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.

FIG. 2 shows 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.

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

The secondary filters Fs I to Fsn of the frequency diversity receiver 3 determine disjoint subbands, included in the aforementioned main bandwidth of the main frequency filter Fp.

The secondary filters FsI to Fsn all receive the main pulse signal Spf via the point J and deliver 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 BPsI, BP s2 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 Fs I, Fs2 and FS3 of a 3-way VF frequency-diversity receiver 3,

VF2 and VF3. The three sub-bands BPsI, 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, a form of a pulse among the pulses constituting the secondary pulse signals Ssf1, Ssf2 and Ssf3.

The detection and filtering circuits adapted Fa 1 to Fan are capable of delivering successions of pulses P 1 to Pn when they receive secondary filters Fs I to Fsn, via amplifiers A 1 to An, pulses whose shape corresponds to an expected form or approximately to such an expected form, i.e. the expected pulses of the secondary pulse signals Ssfl to Ssfn.

The detection and filtering circuits adapted Fa 1 to Fan may contain, for example, a series energy detector with an envelope detection and filter circuit adapted to the shape of the envelope of the expected pulses.

FIGS. 4b, 5b and 6b respectively show, in correspondence with FIGS. 4a, 5a and 6a, the shape of FIG. of a succession of expected successions pulses P l, P2 and P3 out of three adapted envelope detection and filter circuits FaI, Fa2 and Fa3 of the three channels VFl, VF2 and VF3 above.

The successions of expected pulses P l to Pn, for example the succession of taps P l, P2 and P3, are identical and correspond temporally.

The summation circuit 7 receives the successions of expected pulses P l to Pn and delivers at its output a signal SOM corresponding to the addition of the successions of taps P l to Pn. FIG. 7 is an example of the shape of a well

SOM of a signal SOM corresponding to the addition of three corresponding pulses from the three adapted envelope detection and filtering circuits FaI, Fa2 and Fa3 of the three VF channels l, VF2 and VF3 mentioned 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 generator circuit 1 1 in order to reconstitute an expected output binary signal Bs on the output L. This random sequence pre-programmed 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 generating circuit 1 1 is synchronous and in phase with the PN sequence used by the associated transmission device.

Insofar as the aforementioned 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 described 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

1. Device for radio frequency 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, characterized in that it further comprises, between the capture 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 (Fs I ) whose input is connected to the output of the main filter (Fp) and a suitable envelope detection and filtering circuit (FaI) connected to the output of the secondary frequency filter and a summation circuit (7) whose inputs are connected to the outputs of said adapted 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 add the signals from the envelope detection and filtering circuits adapted and delivering to said correlation receiver the resulting signal.

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 in a predefined main frequency band, dividing said main frequency band into disjoint frequency subbands, detecting a predetermined shape signal in each frequency band, summing the detected signals, and despreading or demodulating the summed signal by applying a predefined random sequence and outputting an output signal.