Method of synchronizing a digital signal receiver

Details Method of synchronizing a digital signal receiver Method of synchronizing a digital signal receiver

1998-01-13

1999-11-16

Chin, Stephen

Pulse or digital communications

Receivers

Particular pulse demodulator or detector

375368, 370514, 370520, H04L 2706, H04L 700, H04J 306

Patent

active

059870770

DESCRIPTION:

BRIEF SUMMARY
PRIOR ART

The invention is based on a method for precise chronological synchronization of a receiver for digital signals, as generically defined by the preamble to the independent claims. From Published German Patent Application DE 41 28 713 A1, a method is known in which an item of correction information for synchronizing the receiver is derived from the location of a first significant energy component in the channel impulse response. The channel impulse response is ascertained with the aid of an inverse fast Fourier transform (IFFT) from the sampling values of the channel frequency response. An estimate of the channel frequency response can be calculated from the correlation of a received reference signal with a reference signal stored in memory in the receiver. In the known method, the necessary calculations for the inverse Fourier transform and the determination of the correction information from the channel impulse response are performed in a separate signal processor.


ADVANTAGES OF THE INVENTION

The method of the invention has the advantage over the prior art that the correction information for synchronizing the receiver is calculated directly from the sampling values of the channel frequency response, so that the explicit calculation of the channel impulse response via the inverse Fourier transform (IFFT), which is expensive with regard to the computer capacity and memory needed, becomes unnecessary. Thus the separate signal processor for calculating the IFFT and for determining the correction information in the time range, required in receivers of the prior art, also becomes unnecessary.
A further advantage of the method of the invention is considered to be that determining the correction information from the center of distribution of the squared channel impulse response furnishes more accurate results, less vulnerable to perturbation, than determining the location of the first significant energy component in the channel impulse response, since in the method of the invention an average of many values is obtained.
In the dependent claims, advantageous further features of the method of the invention are described. claim 2, for instance, makes it possible to calculate the correction information by a method which is simplified over that disclosed in claim 1 and for which an advantageous device, because it is simply to realize, is described in independent claim 6. In claim 3, a further simplification is disclosed, with recourse to the Cordic algorithm known from the literature.
Further advantageous aspects of the method of the invention, which are described in claims 4 and 5, are obtained by further simplifications. These make it possible to perform the calculations required for determining the correction information with a minimum of expense for circuitry. A device for the method of claim 4 that entails only slight expenditure for circuitry is disclosed in independent claim 7.


DRAWINGS

Exemplary embodiments of the invention are shown in the drawing and described in further detail in the ensuing description.
FIG. 1 shows a device for conversion of the method of claim 3;
FIG. 2 shows an advantageous embodiment in terms of circuitry for the Cordic algorithm known per se; and
FIG. 3 shows a circuit for converting the values, determined by the Cordic algorithm, into the desired correction information.


DESCRIPTION OF THE INVENTION

The present invention has the object of accurate chronological synchronization of a receiver for digital signals, while avoiding the inverse Fourier transform used in receivers of the prior art, which requires intensive computation. For implementing the accurate chronological synchronization in a receiver, the frequency response of the channel on the matrix of the discrete Fourier transform used is ascertained by correlating a received reference symbol with a reference symbol stored in memory in the receiver. An approximation for the center of distribution of the squared channel pulse response can be calculated, with the aid of the relation. ##EQU1## from the complex samp

REFERENCES:
patent: 5245611 (1993-09-01), Ling et al.

Affiliated with

Also associated with

Rating

Method of synchronizing a digital signal receiver does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of synchronizing a digital signal receiver, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of synchronizing a digital signal receiver will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1333954