Pulse or digital communications – Repeaters – Testing
Patent
1995-11-28
1998-03-10
Chin, Wellington
Pulse or digital communications
Repeaters
Testing
375367, 371 471, 371 54, 370515, H04B 169, H04B 346
Patent
active
057270180
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a process for obtaining a signal indicating a synchronization error between a pseudo-random signal sequence from a transmitter and a reference pseudo-random signal sequence from a receiver using a measuring device on the receiver end.
German Patent Document No. DE 2,359,716 C3 discloses a measuring device designed as a bit error measuring device because it performs a bit-by-bit comparison of a pseudo-random signal sequence transmitted over a measuring distance with a reference pseudo-random signal sequence generated at the receiving end. An error signal sequence is formed from this bit-by-bit comparison of the two pseudo-random signal sequences and is then analyzed in a circuit configuration to determine whether it matches the pseudo-random signal sequence. If they match, a synchronization error is deduced if a bit error is indicated at the output of the bit error measuring device at the same time.
Furthermore, European Patent Document No. EP 408,936 A2 discloses a process for detecting a character pattern in a data stream. The bit sequence occurring in the data stream is compared with the bit sequence that is sought, so that if the bits in the two patterns match, a corresponding identifier is retransmitted from level to level in a shift register as long as there is an uninterrupted match between the incoming bits and the corresponding bits of the bit pattern that is sought. Retransmission of the so-called identifier in the shift register is interrupted when a single bit does not match. If the identifier occurs at the last level of the shift register or at another defined level, this is a sign that the bits in the data stream match the bits in the bit pattern being sought. Otherwise, it is interpreted as a synchronization error.
The process described above is advantageous since it permits reliable differentiation between so-called bundle errors and synchronization errors between the transmitter and receiver and also works at a relatively high speed in comparison with older known processes. But with regard to time, the known process always requires at least an analysis of the length of the pseudo-random signal sequence in order to detect the synchronization error, so the synchronous status can be restored only after a certain amount of time. This entire period of time is lost with regard to the time for monitoring the quality of a digital signal transmission line and therefore the quality of the measurement results is reduced.
SUMMARY OF THE INVENTION
The present invention improves on the known process in such a way that a synchronization error between a pseudo-random signal sequence from a transmitter and a reference pseudo-random signal sequence from a receiver can be detected more rapidly so the synchronous status can be restored relatively quickly.
According to an embodiment of the present invention, each of the successive sections of the reference pseudo-random signal sequence is cross-correlated with the received pseudo-random signal sequence, yielding partial cross-correlation functions which are added together to obtain a sum cross-correlation function. The maximums of the sum cross-correlation function are detected and monitored for their occurrence in time, and if at least three maximums in the sum cross-correlation function do not occur at the correct time, the signal indicating the synchronization error is generated.
An important advantage of the process according to the present invention is that a synchronization error can be detected relatively quickly, so that measures known from the above-mentioned publication for synchronization between the transmitter and receiver can then be taken. The time for determining the occurrence of a synchronization error in the process according to the present invention is determined by the number of partial cross-correlation functions used to form the sum cross-correlation function. A synchronization error can be detected more rapidly if more partial cross-correlation functions are generated. The
REFERENCES:
patent: 4441192 (1984-04-01), Kita et al.
patent: 4553251 (1985-11-01), Hartmann
patent: 4567588 (1986-01-01), Jerrim
patent: 4601047 (1986-07-01), Horwitz et al.
patent: 4644523 (1987-02-01), Horwitz
patent: 4701939 (1987-10-01), Stutt et al.
patent: 5146462 (1992-09-01), Cucchi
patent: 5199050 (1993-03-01), Linsky
patent: 5392314 (1995-02-01), Wolf
patent: 5504781 (1996-04-01), Wolf
A. Wolf, "Messprazision auf breitem band," Telecom Report, vol. 14, No.2, pp. 104-107 (Mar./Apr. 1991).
Arweiler Hans-Werner
Wolf Andreas
Chin Wellington
Corrielus Jean B.
Siemens Aktiengesellschaft
LandOfFree
Process for obtaining a signal indicating a synchronization erro does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for obtaining a signal indicating a synchronization erro, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for obtaining a signal indicating a synchronization erro will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-146225