CN102543129A

CN102543129A - Run length rate (RLR) modulation data recording method

Info

Publication number: CN102543129A
Application number: CN2010106213342A
Authority: CN
Inventors: 徐海峥; 许斌; 刘伟; 陈垦
Original assignee: BEIJING TONGFANG OPTICAL DISK Co Ltd
Current assignee: BEIJING TONGFANG OPTICAL DISK Co Ltd
Priority date: 2010-12-24
Filing date: 2010-12-24
Publication date: 2012-07-04

Abstract

The invention relates to a method for realizing modulation coding of a digital storage product. In the digital storage product, modulation coding is required to be performed on user information to meet channel transmission limit and digital clock restoring performance, and a digital clock can be well restored by generally adopting a run length limit coding form. The method designs a method for realizing modulation coding on the basis of meeting a clock restoring requirement, i.e., a run length rate (RLR) modulation coding method. The method comprises the following steps of: (1) performing RLR modulating coding on binary information which is subjected to error correction coding; and (2) controlling the recording mark length of a physical recording medium and the formation of a microstructure by using data information which is subjected to RLR rate modulation coding.

Description

The recording method of a kind of brigade commander's ratio modulating data

Technical field

The present invention relates to digital storage technique, more specifically, relate to the digital storage technique that adopts CD or hard disk.

Background technology

The modulating-coding that traditional stored digital product (like CD, disk) adopts all is two run length (RLL (d, the k)) modulating-codings made.Wherein d and k are meant between two adjacent 10 the minimum d of number, are no more than k at most.What adopt such as CD is that code check is 8/17 RLL (2,11) EFM sign indicating number, and DVD adopts 8/16RLL (2,11) EFM+ sign indicating number etc.In above-mentioned stored digital product, user data is to represent with the micromorphologic variation of record symbol.In the conventional digital storage products, user data characterizes the binary data sequence after ovennodulation with the variation of record symbol length.In the run length modulation coding method; Change the length of record symbol through segmentation; Or change other micromechanisms, such as can perhaps, perhaps in the record symbol, mixing controllable impurity through changing the width or the degree of depth of record symbol to record symbol sublevel; Thereby change the resolution of run length, improve capacity density.But owing to receive the restriction of read-out system clock recovery, the resolution of run length can not infinitely improve; And because the restriction of read-out system, excessively the run length of segmentation will face the pressure of the signal to noise ratio (S/N ratio) of rapid decline.

The run length ratio modulation coding method that the present invention proposes.On the basis of taking into account read-out system clock recovery requirement, with the ratio modulation record data of run length.

Description of drawings

Fig. 1 is a run length modulation rate method synoptic diagram of the present invention;

Fig. 2 is the step synoptic diagram of run length modulation rate method of the present invention.

Summary of the invention

The present invention provides a kind of run length ratio modulation coding method that is applicable to the stored digital product, and this method comprises run length modulation and ratio brigade commander modulation.Distance of swimming modulation is used for satisfying the restriction of stored digital channel, and the ratio modulation is in order to improve code efficiency.

(summary of the invention detailed annotation)

For guaranteeing the correct clock recovery of read output signal, generally adopt phaselocked loop (PLL) technology.In the phase locking process, need the fixedly phase feedback of multiple, generally get cycle signal zero-cross point, and the zero crossing position is the integral multiple of lowest common multiple.In traditional run length (RLL) modulation, generally the change location of the number of winning the confidence (" 0 " change " 1 " and " 1 " change " 0 ") is as the sampled point of loop feedback.In run length ratio modulation (RLR), generally set the sampled point of the change location (like " 0 " change " 1 ") of certain signal as the phase loop feedback.

Behind the feedback point of setting the phase loop sampling, the parameter that modulate as the run length ratio other position of using signal to change.Because the position that the phase loop feedback is not used the modulation of run length ratio; Its location parameter does not receive phase loop to feed back the restriction of minimum common divisor; Do not influence the recovery of clock signal so the coding site of run length ratio modulation can enough segment, the resolution of its segmentation is only relevant with the characteristic and the read output signal ability of processing of medium.

The method of its run length ratio modulation is explained as follows:

At first, shown in figure (1), the run length that medium write down can be set at mT, nT, pT...... (m, n, p are positive integer) respectively, and the zero crossing position of mT, nT, pT...... can be used as the sampled point of phase-locked loop feedback.

Secondly because recording medium is generally with the recorded information of two states, Ru Keng, bank alternately, the variation of physical parameter direction; Or with the continuous variation of two states; Wait canned data like the variation of polarization angle, the variation of the record pit degree of depth; So between twice clock recovery feedback point, there is a rollback point of medium parameter alternate, the position of this point can be confirmed by parameters such as length or area integrals.The position mark of this point is the ratio parameter in the run length for this reason, promptly is designated as K=m1/m2, i.e. run length ratio modulation.

Method of the present invention may further comprise the steps successively, as scheming (2):

Step 1: produce binary data sequence through run length modulation back through the binary data sequence after the Error Correction of Coding;

Step 2: the specific brigade commander's sequence in the binary data sequence that step 1 generates adopts the modulation of brigade commander's ratio;

Step 3: the sequence that combining step 1,2 produces, carry out the DC control adjustment, make it to satisfy the dc balance requirement of read-out channel;

Step 4: through after the step 3, output distance of swimming sequence, and utilize this sequential recording device to form the record symbol of length variations, microstructure change.

Specific embodiment:

Here introduce a specific embodiment that uses content of the present invention, to help to understand content of the present invention and spirit.Need to prove that following specific embodiment is to use a concrete case of content of the present invention, present embodiment is not contained all the elements of the present invention.The present invention does not terminate in content in the present embodiment.The specific embodiment that all use content of the present invention and spirit is included in the scope of patent protection of the present invention.

Be the particular content of present embodiment below:

If needing the data recorded sequence is B1, B2, B3.......B1 representes a byte, contains the information of 8bit;

Adopt the run length modulation to generate b1, b2, b3...... the B sequence.B representation unit record symbol.The run length modulation has following characteristics: a) this modulated process is only controlled maximum run length, does not limit minimum run length; B) can get the high modulation code check, b both can be set to 0,1 two kind of symbol, also can be greater than two kinds of symbols, and then modulating code check can be greater than 1.

The distance of swimming that keeps the b sequence, to the modulation of the The data distance of swimming ratio in the distance of swimming, as a kind of cycle of establishing the phase-locked loop feedback be 3T, the ratio modulation is set at following ratio representes:

The source code word	Linear ratio's value	The ratio modulation	The ratio modulation code word
				000	0.0	0.15	1∶2
001	0.125	0.25	3∶5
				010	0.25	0.35	5∶7
011	0.375	0.45	11∶13
				100	0.625	0.55	13∶11
101	0.75	0.65	7∶5
				110	0.875	0.75	5∶3
111	1.0	0.85	2∶1

Code word after the ratio modulation is recorded on the medium.

Readout and recording process are opposite.Behind the read-out system read output signal,,, return suitable source code word through comparer, decoding through the ratio rate score of electric circuit inspection signal.

Claims

1. run length ratio modulating-coding implementation method is characterized in that, said method comprising the steps of:

A) for satisfying channel restriction at first carrying out run length ratio modulating-coding;

B) satisfying on the basis of clock recovery, with the ratio recorded information of run length.

C) in modulated process, the run length of integral multiple is used for clock recovery information, and ratio-recording run length is used for recorded information;

D) realization of run length ratio is based on the characteristic of reading of medium, and is not only relevant with the length of time shaft, and relevant with the area integral of signal.

2. according to claim 1, it is characterized in that, comprise the run length of fixed integer multiple and the run length of variable multiple in the code word of distance of swimming rate code.

3. according to claim 1, it is characterized in that, through increasing the segmentation number of distance of swimming ratio, can under equal conditions increase the code check of modulating-coding.

4. according to claim 1, it is characterized in that run length ratio signal is the dimensionless scaling signal at the microcosmos area of record, irrelevant with read-out system, but the signal to noise ratio (S/N ratio) of enhanced system.

5. according to claim 1, it is characterized in that, be used to control laser recorder to form the record symbol through the data sequence after the modulation of distance of swimming ratio.