RU96101192A - ALARM CHANNEL PACKAGE FOR A COMMUNICATION SYSTEM WITH A REFERENCE SIGNAL, MODULATED BY LAW, DEPENDING ON TIME - Google Patents

Claims (22)

1. A signaling channel packet for a communication system, characterized in that it contains a reference signal modulated in accordance with a modulation law representing a given function (f) versus time within the packet.  2. The signaling channel package according to claim 1, characterized in that the reference signal is frequency-modulated.  3. The signaling channel packet according to claim 2, characterized in that the modulation law is a linear function (f) of time.  4. The signaling channel package according to claim 3, characterized in that the modulation law is used in two quadrature channels (1, Q), and two separate functions are used for each channel.  5. A device for estimating a Doppler shift of a carrier for transmitting a signaling packet according to any one of claims. 1-3, characterized in that it contains a local oscillator (VCO), a mixer (M) for receiving a carrier and an output signal of a local oscillator (VCO), a filter (BP) for receiving the output signal of a mixer (M) and generating an intermediate frequency signal (IF), analyzer circuit (MF1, MF2, Mf3, CORR) for receiving an intermediate frequency signal (IF) and generating a shift signal (SN) characterizing the frequency shift due to the Doppler effect between the theoretical frequency value (fT) and the frequency of the intermediate frequency signal (IF) control circuit (CC) for controlling the local oscillator (V СО) to obtain an estimate of the Doppler shift from the generated shift signal (SN).  6. The device according to p. 5, characterized in that the control circuit (CC) provides control of the local oscillator (VCO) to reduce the mentioned frequency shift.  7. The device according to claim 5 or 6, characterized in that the analyzer circuit comprises at least a first filter (MF1) tuned to said reference frequency with a center frequency equal to said theoretical frequency value (fT) and a correction circuit (CORR ) to form the first shape factor (W1) of the output signal of this filter, and the control circuit (CC) provides local oscillator control to maximize the aforementioned first shape factor (W1).  8. The device according to p. 7, characterized in that the control circuit (CC) provides local oscillator control (VCO) by sequential approximation, introducing frequency correction on each side of the frequency, which provides the largest form factor (W1) in order to carry out repeated search for the largest form factor, and sequential search procedures are carried out with decreasing values of the frequency correction until a predetermined correction threshold is reached. 9. The device according to claim 7, characterized in that the shift amplitude (Δf) has a value substantially equal to the maximum Doppler shift of the intermediate frequency signal (IF), and that it further comprises a second and third filter (MF2, MF3) configured to said reference signal and having a center frequency equal to said theoretical frequency value (f _t , respectively reduced and increased by said shift amplitude (Δf), wherein the correction circuit determines, in addition to the first shape factor (W1), a second and third coefficient s of the waveform (W2, W3) of the output signal of the second and third tuned filters (MF2, MF3), respectively, and generates the said shift signal (SH) proportional to the reciprocal of the center of gravity of the center frequencies of the tuned filters (MF1, MF2, MFZ), weighted by the corresponding coefficients forms (W1, W2, W3).  10. The device according to p. 9, characterized in that the control circuit (CC) controls the local oscillator (VCO) so that the intermediate frequency signal (IF) has a frequency increased by the frequency of said shift. 11. A device for synchronizing with a carrier signal for transmitting a signaling packet according to any one of claims 1 to 3, wherein said reference signal has a duration T and is transmitted periodically with a repetition period Tg, and the measurement interval has a predetermined duration greater than or equal to T + Tg characterized in that it contains a local oscillator (VCO), a mixer (M) for receiving a carrier signal and an output signal of a local oscillator (VCO), a filter (BP) for receiving the output signal of a mixer (M) and generating an intermediate frequency signal (IF), a circuit analyzer (MF 1, MF2, MF3, CORR) for receiving an intermediate frequency signal and generating a frequency change signal (CF) if no reference signal is detected, or a frequency shift signal (SN) representing a shift between the theoretical frequency value (f _t ) and the frequency of the intermediate signal frequency (IF) control circuit (CC) for controlling the local oscillator (VCO) so that it tunes to the carrier and then, after a measurement interval, either tunes to another carrier in the presence of a frequency change signal, or decreases the value of the mentioned shift signal tones (SH) in the absence of a frequency change signal (CF). 12. The device according to claim 11, characterized in that the analyzer circuit comprises at least a first filter (MF1) tuned to said reference signal with a center frequency equal to the theoretical frequency value (f _t ) and a correction circuit (CORR) for generating a first shape factor (W1) of the output signal of this filter, and a control circuit (CC) controls the local oscillator to maximize said first shape factor (W1).  13. The device according to p. 12, characterized in that the control circuit (CC) controls the local oscillator (VCO) by successive approximations, introducing frequency correction from either side of the frequency that forms the maximum shape factor (W1), to search again for the maximum shape coefficient moreover, sequential search procedures are carried out with decreasing values of the frequency correction until a predetermined correction threshold is reached. 14. A device for synchronizing with a carrier signal, providing the transmission of a signaling packet according to any one of paragraphs. 1-3, and said reference signal is transmitted periodically with a repetition period Tg, characterized in that it contains a local oscillator (VCO), a mixer (M) for receiving a carrier signal and an output signal of a local oscillator (VCO), a filter (BP) for receiving the output of the mixer (M) and generating an intermediate frequency signal (IF), an analyzer circuit (MF1, MF2, MF3, CORR) for receiving an intermediate frequency signal and generating a frequency shift signal (SH) representing a time interval between reception of two consecutive signaling packets, a control circuit ( SS) to control the local oscillator (VCO) to reduce the shift between the frequency shift signal (SN) and said repetition period T _g .  15. Device for estimating a transmission channel using a carrier signal, providing the transmission of a signaling packet according to claim 2 or 3, characterized in that it contains a local oscillator (VCO), a mixer (M) for receiving a carrier signal and a local oscillator output signal (VCO), a filter (BP) for receiving the output signal of the mixer (M) and generating an intermediate frequency (IF) signal, an analyzer circuit for receiving an intermediate frequency (IF) signal and converting it into a band of modulating signals to form the spectrum of the mentioned channel, control circuit (CC) for control heterodyne (VCO) to determine the estimation of the channel, based on the received spectrum of this channel. 16. The device according to p. 15, characterized in that said reference signal has a frequency response with constant slope (-μ), the control circuit (CC) controls the local oscillator (VCO) so that it forms a frequency whose slope characteristic (μ) is opposite to the corresponding characteristic of the reference signal, starting from the reception of this signal along the shortest path t _{o of the} mentioned channel, the channel spectrum has a set of spectral lines, each of which is identified by the frequency r _i and amplitude h _i , and the particular spectral line co corresponds to the path t _i and has a frequency associated with the length of this path, and the control circuit generates an estimate, determining each propagation path t _i by its contribution, which is proportional to the amplitude of the corresponding spectral line h _i and its time delay τ _i , which has a value ( r _i th) / μ, for all values of i from 0 to n, if (n + 1) individual propagation paths are considered. 17. The terminal of a mobile radio installation intended for receiving a signaling packet according to claim 4, characterized in that it contains means for receiving a packet of this type, known as a FCCHd packet signal, for receiving (17,18) in two channels (1 ) and (Q) a quadrature receiver of a plurality of samples sufficient for subsequent calculations and storing (22, 23) of these samples S _I (t) and S _Q (t), and t is a time variable; to obtain (24) and memorize (25) various products S _I (KT) • S _Q (KT), and KT denotes a time variable (discrete representation); for digital low-pass filtering (26) to exclude the highest frequency component from each product obtained, for spectral analysis (28) of the received filtered signal (27) to determine the difference (f _I ) between the instantaneous frequencies of two quadrature channels (1, Q) at the time of reception; to calculate (32) at a known duration (T _c) batch FSSNd signal (10) and the instantaneous frequencies (f _I) and (f _Q) at the end of the transmitted burst, the time interval (τ) between the real start of the batch FSSNd and the start signal said trick using the following equation:

where f _{I is} determined by spectral analysis, and f _{I is} assumed to be larger than f _Q ,
and then, to synchronize (34) the terminal with the start of this burst signal FCCHd, which is now known.  18. The terminal according to claim 17, characterized in that it comprises means for determining the absolute value of the Doppler shift (d) by receiving (pos. 22, Fig. 9; pos. 23, Fig. 10) a complete packet signal FCCНd according to one of two channels of the quadrature receiver by storing the samples and then, if necessary, processing (35-39, 63-68) this stored signal, which is exposed to the mentioned Doppler shift (d) in order to save in it only the cosine or only the sinus component (2πdt ) to which the phase term (φ) is added, and finally to perform spectral analysis (69) of the received signal to determine the value of the aforementioned Doppler shift (d), to determine the sign of this Doppler shift (d) by similarly calculating two Doppler shifts (d1) and (d2) at substantially long consecutive intervals, for example, in order at least one to several seconds, and calculating (41, 42) the difference between the absolute values ([d2] - [d1]) of these two shifts in order to determine the direction of change of the Doppler shift (d) and, therefore, its sign. 19. The terminal according to claim 18, characterized in that it comprises means for compensating the Doppler frequency shift (d) using, for demodulation (46, 51, 52), the information signal received from the satellite (43, 44, 45) of the local oscillator (48), whose frequency is not an ordinary fixed frequency (f _o ), but equal to a frequency (f _o ) having a Doppler frequency shift (d).  20. The terminal according to claim 19, characterized in that to compensate for the Doppler shift in real time over the entire interval of the satellite’s movement, the terminal comprises means for generating Doppler correction (d) input to the control input (49) of the local oscillator (48) demodulator, and means for real-time correction using a logic device (54) for automatically tracking the Doppler shift (d) in accordance with the known offset of a particular satellite and using a limited number of Doppler shift measurements n (d).  21. The terminal according to claim 20, characterized in that the logic unit (54) for monitoring the Doppler shift in real time includes a memory (56) for storing a table (57) of known changes in time of the Doppler shift for different maximum elevations of each satellite, " the terminal is designed to perform a limited number of measurements of the Doppler shift and memorization in volatile memory (58, 59), as well as to compare the results of these measurements in the logic block (60) with previously stored data in the table (57) for determining ELENITE characteristics of the Doppler shift change required for use in this case, the second computing unit (61) for predicting and outputting (49) the Doppler shift correction voltage to the local oscillator (48) demodulator.  22. The base station of a mobile radio installation, characterized in that it contains means for transmitting a signaling packet according to any one of paragraphs. 1-4.