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# Signal-to-noise ratio of pilot tracking tones embedded in binary coded signals

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## Abstract

The signal-to-noise ratio of pilot tracking tones embedded in binary coded formats has been assessed. It has been found that the signal-to-noise ratio can be improved when the redundancy of the code is increased. Since the signal-to-noise ratio of the pilot tracking tone limits the maximum attainable bandwidth of the servo system, a compromise has to be found between the redundancy of the code and the performance of the servo system. The signal-to-noise ratio of pilot tones based on the polarity switch technique, which is attractive as no lookup tables are required for encoding and decoding, is substantially smaller than that of codes based on the fixed disparity format.

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... Finally, the power spectrum of the process t, generated by the finite state machine with transition matrix B is proportional to S,(O) = i R(lkl)e-2"'ke, (1. 6) where k=-m R(k) = uTFBku, k =O,l;.+, (1.7) with F=diag(q,,q,;.., qw) and u=l/p[-m,-m+l;.., m -1, mlT (m = [ pb 1). ...
... In digital magnetic recorders part of the information storage capacity is exploited for recording servo position information. This information is often recorded as a low-frequency tone, ,usually called pilot tone, see [6]. The principle of operation is as follows. ...
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The eigenstructure of bidiagonal Hessenberg-Toeplitz matrices is determined. These matrices occur as skeleton matrices of finite-state machines generating certain asymmetrically DC-constrained binary sequences that can be used for simulating pilot tracking tones in digital magnetic recording. The eigenstructure is used to calculate the Shannon upper bound to the entropy of the finite state machine as well as the power spectrum of the maxentropic process generated by it.
... The run-length constraints [24], [30] bound the minimal or maximal lengths of certain types of channel subsequences, whereas the spectral constraints include dc-free [21] and higher order spectral-null constraints [22], [23], [31]. The spectral constraints also include codes that produce spectral zero at rational submultiples of symbol frequency [29] as well as constraints that give rise to spectral lines [16]. Very often, more than one constraint is imposed on a recorded sequence. ...
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Chapter
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Statistics of regenerative digital transmission Codes for zero spectral density at zero frequency
• W R Bennett
• G L Pierobon
W. R. Bennett, " Statistics of regenerative digital transmission, " Bell Syst. Tech. J., vol. 37, pp. 1501-1542, Nov. 1958. [ 101 G. L. Pierobon, " Codes for zero spectral density at zero frequency, " IEEE Trans. Inform. Theory, vol. IT-30, pp. 435-439, March 1984.
Alles uber Video (Philips Taschenbucher
• H Bahr
Method and apparatus for recording a digital information
• M H H Hoefelt
• E De Niet
• A M A Rijckaert