Data scrambler

Author: w | 2025-04-25

Data SCRAMBLER App. Contribute to Akashdasbd/data-scrambler development by creating an account on GitHub.

Akashdasbd/data-scrambler: Data SCRAMBLER App - GitHub

This page compares Synchronous scrambler vs Self synchronizing scrambler and mentions difference between synchronous scramblerand self synchronizing scrambler used in data communication including their advantages (benefits) and disadvantages (drawbacks).Introduction:In wireless communication, scrambler is used to remove long sequence of ones and zeros by randomization of data.It is used before FEC encoder or modulator or line encoder. Scrambler is used at the transmitter side.Descambler is used at the receiver side to recover original bit patternfrom randomized data bits. The same is shown in the physical layer of wimax as per IEEE 802.16 standard.There are two main functions of scrambler in the system. • It provides more transitions in the data by removing long string of similar data bits i.e. 1s and 0s. This helps in accuate timing recoveryat the receiver. • It disperses energy on carrier signal and hence reduces ICI (Inter Carrier Interference). • The scrambling concept is used in R8ZS and HDB3 coding techniques to maintain DC balance. Synchronous scrambler | Additive scramblerIt uses LFSR (Linear Feedback Shift Register) togenerate PRBS (Pseudo Random Binary Sequence) sequence or pre-stored PRBS is used.Synchronous scrambler transforms data stream by using modulo-2 sum of input data andPRBS sequence as shown in the figure. Hence synchronous scrambler is also knownas additive scrambler. The circuit is as per PRBS generator 1 + X14 + X15 polynomial.Figure-1 : Synchronous scrambler and descrambler circuit The same SYNC word is used for scrambler and descrambler at the transmit and receive end to enablesynchronous operation of both.Advantages of Synchronous scramblerFollowing are the benefits or advantages of Synchronous scrambler. ➨It offers error detection capability. ➨It removes long string of zeros and ones and provide more transitions in the data pattern to makesynchronization easier without the need of separate clock signal. ➨It does not have any DC components. Disadvantages of Synchronous scramblerFollowing are the drawbacks or disadvantages of Synchronous scrambler. ➨It fails to generate random sequences in worst case conditions. ➨It should be reset by SYNC word otherwise massive error propagation occurs. Self synchronizing scrambler | Multiplicative scramblerThe scrambler and descrambler circuit for self synchronizing scrambler and descrambler is shown inthe figure. It does not require frame SYNC word for synchronization unlike synchronous scrambler.Hence it is called self-synchronizing scrambler.This scrambler performs multiplication of input by transfer function in Z-space.Hence self synchronizing is also known as Multiplicative scrambler.Figure-2 : Self synchronizing scrambler and descrambler circuit They are defined by polynomial 1 + X14 + X15.Multiplicative scrambler is recursive where as descrambler is non-recursive.Advantages of Self synchronizing scramblerFollowing are the benefits or advantages of Self synchronizing scrambler. ➨It does not require SYNC word called "SEED" for its operation unlike synchronous scrambler. ➨The other advantages are similar to the one listed in synchronous scrambler Long as no line errors occur. FIG. 2 is a simplified block diagram of the improved scrambler according to this invention. To the basic scrambler 25, analogous to elements 11, 12, and 13 of FIG. 1, are added auxiliary delay unit 26 and monitoring logic 28. Basic scrambler 25 operates as previously described to complement the input data on line 20 in modulo-two adder 22 over control line 24. If the undesirable data input period is longer than the number of stages rovided in the basic scrambler, additional stages of storage or delay are furnished in auxiliary delay unit 26 at the output of basic scrambler 25. There is no direct feedback from auxiliary delay 26 to the data input sequence. However, output leads 27 from delay 26 are spaced from the input to scrambler 25 by the respective lengths of undesired sequences to be monitored. Monitoring logic 28 compares the outputs on leads 27 with the input to basic scrambler 25 and if they continuously match, complements the input data bit over lead 23 at modulo-two adder 21. The undesired sequence is thereby broken up and the output of the system on line 29 is forced to be of relatively long period. The improved descrambler is the same as the scrambler of FIG. 2 with data input 20 and output line 29 interchanged. The arrowheads at points 20, 29 and between adders 21 and 22 are necessarily reversed. Two basic types of self-synchronizing, digital data scramblers have been devised. They are the single-counter and multicounter types. The block diagram of FIG. 2 is regarded as generic to both types. The block diagram of FIG. 3 depicts the single-counter scrambler according to this invention. Here shift register stages SR-l to SRM, generally designated 11, adders 13 and 14 and multipliers 0 through c constitute together the basic scrambler as in FIG. 1. Auxiliary shift register stages SRSl to SR-S2, generally designated 26, constitute the auxiliary delay 26 of FIG. 2. Assume that there are periodic sequences of length S1 and S2, each greater than m, the number of stages in the basic scrambler. Then the output of stage SR-Sl is delayed by S1 bit intervals from the input to stage SR1. Similarly, the output of stage SR-S2 is delayed S2 bit intervals from the input to stage SR1. Monitoring logic comprises single-counter 35 with a threshold reached after t counts, modulo-two adder 32 for comparing the output of stage SRSl with the input to stage SR-l, modulo-two adder 33 for comparing the output of stage SR-S2 with the input to stage SRI, AND-gate 34 for combining the significant nonzero outputs of adders 32 and 33 to reset counter 35. Adders 32 and 33 have nonsignificant or zero outputs when their respective inputs are identical, i.e., when a periodic sequence of length S1 or S2 is present on the data input. In this case there will be no resetting output and counter 35 will advance toward its threshold. 0n the other

Yeapes/data-scrambler: Simple PHP data scrambler project

Data bit and the delayed data bits, spaced along the sequential filter by the lengths of several such deleterious sequence periods, are compared and control outputs are generated whenever there is a match. A single synchronously advanced counter is allowed to reach a predetermined threshold in the presence of a sustained matching control signal. Upon reaching threshold the prevailing data bit is complemented to prevent an undesired input sequence from appearing on the channel. The counter is reset when it reaches threshold as well as in the absence of a matching control signal. According to another aspect of the invention, the number of stages of delay in the sequential filter is also extended, as necessary, beyond the range of the basic scrambler and descrambler to the length of the longest periodic data sequence it is desired to break up. Comparison circuits, including zero-level slicers, are established between the input to the basic scrambler and taps on the extended scramber corresponding to the length of each undesired periodic sequence. An individual monitoring counter with preassigned threshold is then provided for each comparator circuit. The counter outputs are further buffered to complement the prevailing data bit whenever any of the counters reaches threshold. At the same time all counters are reset. The corresponding descrambler in either case is the complement of the transmitting scrambler with feedforward paths rather than feedback paths. Whereas the length of the basic scrambler is determined in the binary case by the shortest random channel sequence allowable, the length of the extended scrambler is determined by the length of the longest undesired sequence. However, it will be understood that where the basic scrambler is as long as, or longer than, the undesired sequence the monitoring tap may be included within the length of the basic scrambler. An advantage of this invention is that the level of tones produced by the unscrambled sequence is reduced by a factor equal to the ratio of the length of the unscrambled periodic sequence to that of the scrambled sequence. The scrambled sequence will also have as many low-level tones as the number of high-level tones in the unscrambled sequence multiplied by the reciprocal of this same factor. Another advantage of this invention is that the scrambled sequence will have half as many transitions for synchronization purposes as there are digits in the sequence. A feature of this invention is that scramblers and descramblers constructed according to the principles of this invention are capable of implementation by wellknown logic circuits. DESCRIPTION OF DRAWING Additional objects, features and advantages of this invention will be appreciated from a consideration of the following detailed description and the drawing in which: FIG. 1 is a block diagram of the basic data scrambler disclosed in the cited copending patent application; FIG. 2 is a generalized block diagram of the improved data scrambler according to this invention; FIG. 3 is a block diagram of a single-counter data scrambler according to this invention; FIG. 4 is a block diagram of. Data SCRAMBLER App. Contribute to Akashdasbd/data-scrambler development by creating an account on GitHub. Download Data Scrambler latest version for Windows free. Data Scrambler latest update: Novem

Additive data scrambler a. Make a sketch for an additive scrambler

May be synchronized by transitions in the line sequence in any convenient manner, controls the shifting of registers 41 and 46 and the counting interval of counter 45. The descrambler of FIG. 4 is seen to be substantially the mirror image of the scrambler of FIG. 3. The single-counter scrambler can be expanded to monitor more than two periodic sequences in an obvious manner. Since the single-counter scrambler operates in a way which makes it inconvenient to determine which periodic sequence is present, another embodiment called the multicounter scrambler has been devised to monitor periodic sequences independently. FIGS. and 6 are block diagrams of complementary multicounter scramblers and descramblers. The multicounter scrambler of FIG. 5 is similar to the single-counter scrambler of FIG. 3 in having a basic scrambler register 11 and an auxiliary register 26. One additional stage SR-S is included in auxiliary delay 26 to indicate that any number of individual length sequences can be monitored. For each periodic sequence to be monitored a counter 55 or 56 is provided. The input to each counter is the diiference between the present data digit and the digit transmitted 8, (i=1, 2, N) clock intervals earlier as obtained in modula-two adders 32 or 33. (In modulo-two arithmetic addition and subtraction are equivalent.) Adder 32, for example, takes the difference between the digit at the input to stage SR1 and the output of auxiliary stage SR-Sl. These two points are S1 data intervals apart. If the data sequence has the period S1, these two digits agree and the difference is zero. Then the associated counter will reach threshold I Clock 37, synchronized with the data input, determines the counting rate in any convenient manner. The counter output, applied through OR-gate 57 and lead 36 will complement the sum of the tap outputs from the basic scrambler through adder 31. At the same time all counters are reset over the lower branch of lead 36 and OR-gates, such as those designated 53 and 54. If the respective digits separated by any selected interval S 8 or S fail to agree, then a significant nonzero output appears at the associated adder, such as 32 or 33, and resets the appropriate counter 55 or 56 through OR- gate 53 or 54. Counter thresholds for each counter are selected to have a minimum value equal to one less than the number of stages m in the basic scrambler plus the length of the longest sequence being monitored by any other counter, i.e., If only one period is being monitored, only one counter is employed and the threshold of this counter is chosen to have a minimum value of m. The actual value of the threshold may advantageously be the next higher full count of a multistage binary counter. For example, if 7- and 8-bit periodic sequences are being monitored by a five-stage basic scrambler, then Equation 3 requires a minimum counter threshold of 12 for the counter monitoring the period 7 sequence. The next higher And as part of the theorem, we also say there exists only one such critical state. An example of a critical initial state is illustrated when the data source is binary in the following Table I. A fivestage basic scrambler with feedback from the third and fifth stages toward the input is assumed and a periodic seven-bit data sequence of the form 1001000. The critical state has been determined to be 11001. TABLE I Critical state Key, SR3+ Data SR-5 SR-l SR-2 SR-3 SR4 SR-5 The key signal of column 2 is the modulo-two sum f the bits stored in stages SR3 and SR-S of the same row. For all rows after the top the bit in stage SR-l is the modulo-two sum of the data and key bits of the first and second columns of the row next above. The bits in the remaining stages SR-2 through SR5 of a given row are those shifted one column to the right from stages SR-l through SR-4 of the row next above. The critical state of the top row is seen to be regenerated in the bottom row below the horizontal line and thus the output of the system will remain periodic with a period of seven. The line signal constitutes the bits successively stored in stage SR-l reading from the to of the column down. Thus, the seven-bit periodic data signal 1001000 is translated into another seven-bit periodic line signal 1011001 and is not scrambled when the initial state of the scrambler is 11001. For every periodic input there exists one critical state which will transform, but not scramble, that input into an output of the same period. For any other initial state the input will be scrambled into an output with a period which is the least common multiple of the period s of the input sequence and p 1, Where m is the number of scrambler stages. Once the shortest permissible line sequence is stated, the length m of the scrambler is selected to make the least common multiple of p l and the period s of the periodic input of smallest period larger than that shortest permissible length. For a binary field (p=2) and a transitionless input (which has period 1) a five-stage scrambler yields a sequence of period 2 1=3l and a sevenstage scrambler yields a sequence of period 2' l=127. According to Peterson, there are eighteen choices of coefiicients which will render a seventh-degree polynomial h(x) primitive and irreducible. A choice with the minimum number of nonzero coefiicients yields Equation 2 defines a scrambler like that of FIG. 1 with seven stages SR-l through SR7, a modulo-two adder in position 14 and a modulo-two adder 13 having inputs from taps at the outputs of stages SR-4 and SR7 through multipliers of unity gain at c and c and an output connected to adder 14. The corresponding descrambler is the mirror image of the scrambler with feed-forward rather than feedback paths. The descrambler is self-synchronous as

GitHub - elkasztano/asg-scrambler: data scrambler based on an

In nature. An inverse operation at the receiver recovers the key signal and subtracts it from the channel signal to reconstruct the original data sequence. The channel signal is presumptively free of tone-producing repetitive sequences and synchronization is recovered directly from the channel sequence. According to the above scheme dotting sequences are properly randomized and transitionless sequences are broken up, by monitoring for their presence. It has now been discovered that there exists critical initial states of the scrambler which fail to remap repetitive sequences other than dotting and transitionless sequences into new periodic sequences of longer period. These longer repetitive sequences can also generate deleterious tone levels in the transmitting channel. Such sequences are not ade quately randomized by the scrambler of the cited patent application and may in fact simulate sevenand eight-bit control sequences found in the recently adopted American Standard Code for Information Interchange (ASCII) and other data processing codes. Repetitive occurrence in message data transmission of sequences of these lengths can cause undesirable tone levels in transmission channels. Among these sequences are those for null (0000- 0001), sync (00101100), delete (11111110), idle (1111- and space (0000001). It is therefore an object of this invention to map periodic data sequences of known length into quasi-random periodic channel sequences of much longer periods. These quasi-random periodic sequences at one and the same time will provide transitions for the channel sequence sufficient in number for self-synchronization and random enough in dispersion for avoidance of channel energy concentration. It is another object of this invention to provide general design criteria for the construction of scramblers and descramblers for periodic data sequences of arbitrary length. It is a further object of this invention to guarantee that no channel sequence shorter than some minimum length will be generated regardless of the input data sequence. Such minimum length may be of the order of one hundred or more. SUMMARY OF THE INVENTION According to this invention, self-synchronizing digital data scramblers comprise a basic scrambler of the type disclosed in the cited copending patent application and monitoring logic for detecting the presence of periodic channel sequences of known length and for remapping such detected sequences into new sequences many times the length of the original sequence. The herein-designated basic scrambler comprises a linear sequential filter with feedback paths from selected taps thereon to the input. The corresponding basic descrambler comprises a linear sequential filter with feed-forward paths from similarly selected taps thereon to the outputs. The number of stages of delay in the basic scrambler or descrambler is shown to be a joint function of the shortest allowable channel sequence and of the shortest expected input data sequence. The general solution to the problem of tap selection is discussed herein. According to one aspect of this invention, the number of stages of delay in the sequence filter of the basic scrambler and descrambler is chosen or extended to equal in number the period of the longest data sequence with deleterious tone-producing properties. The input

Design and Implementation of Data Scrambler

AboutBike ModelsSpecificationsTop ComparisonsImagesReviewsNewsDealersAboutBike ModelsSpecificationsTop ComparisonsImagesReviewsNewsDealersThe Ducati Scrambler is a brand of bikes made by Ducati two wheeler manufacturer in India. There are 4 Scrambler models on offer with price starting from Rs. 10,39,068 (avg. Ex-showroom). The cheapest model under the series is Ducati Scrambler Icon with 803cc engine generating 71.87 bhp of power. Whereas the most expensive model is Ducati Scrambler 1100 with 1079cc engine generating 84.48 bhp of power.Ducati Scrambler Price List (2025) in IndiaDucati Scrambler Bike ModelOn-Road PricesDucati Scrambler Icon₹ 10,39,068 *Ducati Scrambler Nightshift₹ 12,00,079 *Ducati Scrambler Full Throttle₹ 12,00,079 *Ducati Scrambler 1100₹ 13,40,000 **Is Avg. Ex-showroom PriceRead MoreDucati Scrambler Price in IndiaFind the Scrambler that Suits Your NeedsWhat are you looking for?Recommended BikeDucati Scrambler IconDucati Scrambler NightshiftDucati Scrambler Full ThrottleDucati Scrambler 1100Price₹ 10,39,068₹ 12,00,079₹ 12,00,079₹ 13,40,000Displacement803 cc803 cc803 cc1079 ccWeight185 kg191 kg185 kg206 kgFuel Tank Capacity13.5 litres13.5 litres13.5 litres15 litresARAI Mileage19 kmpl19 kmpl19 kmpl19 kmplOwner Reported Mileage--------Seat Height795 mm795 mm795 mm810 mmBrake TypeDiscDiscDiscDiscTransmission6 Speed Manual6 Speed Manual6 Speed Manual6 Speed ManualMax Power71.87 bhp @ 8250 rpm71.87 bhp @ 8250 rpm71.87 bhp @ 8250 rpm84.48 bhp @ 7500 rpmScrambler Bikes ComparisonsDucati Scrambler ImagesDucati Scrambler Videos2024 Ducati Scrambler 2G Review | Tested in City, Highway & Off-Road | BikeWaleBy BikeWale Team11 months agoDucati Scrambler ReviewsExpert ReviewsDucati Scrambler User ReviewsDucati Scrambler NightshiftThe Scrambler Nightshift is also equipped with additional aesthetic details, like the front and rear LED position indicators. (only EU homologated)I could feel straightaway that this was a light bike and the flat bars made for a really comfortable riding position, with my feet firmly on the ground.The TFT display is clear and easy to read with everything that you need to know on show. Navigating the display is easy too which is a huge plus point in my book!TFT screen on the 2023 Ducati Scrambler NightshiftThe TFT screen coming into life on start-upPersonally, I like bar end mirrors and with the single round headlight and cool-looking indicators, the front end looks stylish.The sound of the twin-engine on start-up immediately gives you that unmistakable sound that it is a Ducati complimented with the note of the exhaust. They just. Data SCRAMBLER App. Contribute to Akashdasbd/data-scrambler development by creating an account on GitHub. Download Data Scrambler latest version for Windows free. Data Scrambler latest update: Novem

synchronous data scrambler and descrambler

Hand, if neither periodic sequence of length S1 or S2 is present, both adders 32 and 33 will have nonzero outputs which when combined in gate 34 will reset counter 35. Clock 37 provides an output at the data bit rate to advance all shift register stages simultaneously and also counter 35 in the absence of a resetting input. Upon reaching threshold 1, either sequence S1 or S2 being on the data input line, counter 35 produces a significant nonzero output on line 36 which is added in modulo-two adder 31 to the feedback path of the basic scrambler. The present data input bit is thus complemented and the output of the system on line 15 does not include any sequence of period S1 or S2. It should be noted that a period S1 or S2 includes lesser periods which divide it. A period 82:8, for example, includes periods of lengths 2 and 4. Also S1 and S2 must be relatively prime to each other and to the period 2 1 of the basic scrambler. The minimum threshold t for counter 35 has not been determined, but it is known that it need not be longer than where m and S2 have been previously defined. For m=7, 81:7 and 82:8, t=954 maximum. A seven-stage binary counter with threshold t=28 has been found suitable in a practical case without providing unnecessary complementing of the input. Lesser threshold counts may react unfavorably to strictly random data or noise. FIG. 4 illustrates in block diagram form the singlecounter descrambler corresponding to the single-counter scrambler of FIG. 3. The single-counter descrambler comprises a basic descrambler 41, auxiliary delay 46, and monitoring logic including adders 42 and 43, AND-gate 44 and counter 45 with a threshold t. The basic descrambler has shift register stages SR-l through SRM, where M is the same as in the corresponding scram-bler; multipliers 0 through c and modulo-two adders as shown. With coefficients 0 through c chosen according to the same primitive polynomial h(x) as those in the sending scrambler, it is apparent that the same sequence will be reconstructed at the input of adder 49 as formerly existed at the input to the sending scrambler once the initial state of stages SR-l through SRM are purged. Adder 42 has as inputs the received line sequence and the output of auxiliary stage SRSI and therefore has a zero output whenever the present data bit and that S1 bits ago are the same. Similarly, adder 43 has a zero output whenever the line input and the bit S2 data intervals ago match. Since both adders 42 and 43 drive AND-gate 44 a resetting output indicates that sequences of periods divisible into S1 or S2 are absent from the line input. Counter 45 can reach threshold t only when data bits spaced by either S1 or S2 match for t data bit intervals. When 2 counts are made, the line sequence is complemented by adder 49 over lead 39. Clock 47, which