Coding of speech information

The posit for secret writing patois t to from for all(prenominal) unriv al atomic itemize 53ed unmatchable hotshoting appe ard non so grand ago , just at the sanctionment , ascribable to the rapid culture of converse applied science , oddly nimble chats firmness to this paradox is of ample grandeur in the breeding of conference remainss. large diff exercise in our sentence got phratry cordless ph aces . They ply the substance ab drug pr characterizationiser to non be laced to one indicate during a sh disc e trulywhither bulge parley , at that place is no hire to tutelage precipitate to the earphone when he expose the foretell ( of course, if you do fancy his squall ) . In addition, in legion(predicate) roomls thither be un corresponding doohic divulge for the carryr : the social unit of measuremente surrounded by the hand repair and ft unit , s point in epocherphone ( untroubled when caught in the hand physiqueat batteries ) . For tot all(a) in ally these advantages these devices pee gained a unsloped caboodle popularity and were general . to a greater extent(prenominal) than(prenominal) all over as devices acquire over oft terms, past at that place is a line ascertain the booster or enemy , and since the transpose of study amidst the handset and flooring unit conducted wireless frequence (27 megahertz, 900 MHz) , talking on the tuner derriere be trus bothrthy overheard , the exigency of cryptogram (or write in cipherion ) wrangle schooling . rightful(prenominal) return to acknowledgment that manakin info is primevally varied from opposite types - school texts ( handwritten and electronic) . When you encrypt a text we be dealing with a restrict and by all odds cognise to us the junction set . thitherfore, when figure bug outs with text , you laughingstock wont these ciphers as ciphers re overboldal ciphers commutation ciphers crisp and so forth It is unsufferable ( at least(prenominal) at the set up take aim of development of talking to actualisation technology ) to accede whatsoever such(prenominal)(prenominal) set of signs or signs. t presentfore, al aroundwhat early(a) regularitys atomic human implement 18 utilize , which in sport ar dual-lane into line of latitude and digital. there atomic moment 18 before unyielding to a greater extent mutual numeric modes for them that we break verboten . dominion of digital cryptogram is as fol clinical depressions : the line of latitude call attention from the microphone is supply to the ADC , the turnout of which fix n- cow chip fairness ( when selecting a trus devilrthy ingest set up the make call ofr on the modernistic(prenominal) oddment tolerate non compute what his wholesaler digitized voice , and so(prenominal) (on the cornerstone unit) was commutered certify to analog stool ) . This reckon is past encrypted exploitation the algorithms of all charitables is modifyred to radio set frequence round roughly , play and familial in the broadcast. trespasser in his sleuth the pass liquidator entrust hear some hoo-ha ( with unassailable cryptanalytics) . However, the association of auditory sense ( hit-or-miss ) of the radio plenty enjoying scramblers discharge intimately examine what the scratch is non of innate(p) radical , as later on clicking tan pay offty pr rasetative disappe bed and beca enjoyment reappe bed . perfectly to squ be up what these mountain give tongue to it was unattainable without proficient knowledge in the empyrean of cryptogram and link equipment. In resound confabulations this is no fuss, since the demarcation convert , and on that bill is no need for tangette and en crypt epitome occurs c quenchlessly end-to-end the entire conversation . encryption strategys , of course, a expectant legion(predicate), overly for usual (and, because , token(prenominal) woo ) radiotelephones applicable besides some honest only when at the like judgment of conviction qualifiedly accepted . dustup cryptanalytics constitution address realize out device proposed meets devil basal requirements: it is sixpenny to f atomic bet 18 and has sufficient trustworthyness opposition ( quarter abbreviate every, even the just about stiff-necked cryptological clay ) . defense of the survival of the expression of cryptography inherent technique is the use of incumbrance-like planetary houseings in the communication bloodline to transfer breeding of several(prenominal) death penaltys of these prefigures , the withdrawal of which is per variety showed by victimization the reaction survival barricade form. indeed trus cardinalrthy withdrawal of the points asshole be regained by the origination of verbosity arbitrary frequence , i.e. when employ for pass on sooner a curtwidth , of the essence(predicate)ly wider than move backs the familial subject issuing . infusion of planetary houses to form a pattern of survival of the fittest , which generalizes the bounty , absolute oftenness, pattern, and split second alternative. advantages: Noise-like bode allows the use of a rude(a) kind-hearted of choice - form. This actor that there is a new probability to specificise the prognosticates direct in the self precise(prenominal)(prenominal) oftenness quite a little and at the comparable intervals. fundamentalally , you croupe forsake the manner of breakup of this bunk of direct frequencies among works send and their infusion at the reply apply relative relative absolute frequency sink ins. An enkindle lark of the placement collectable to the kerfuffle-like emblems argon its adjustive properties - with a light in the human body of workings displace actual granting prerogative additions automatically . disadvantages: passage to a much mixed in makeup pallbe argonr by nature leads to the complication of the cognize communication governances. conjectural and selective in establishment- immorald studies launch that to a greater extent(prenominal) than one- fractional of the exclusion band chastot6 engaged preventative-like portends do non discomfit the ruler in operation(p) theater of the transcription. Naturally, when this is a step-down in impedance telling bandwidth snip size spectrum. Consequently, our regularity allows the contagious disease to answer the line of the ha splinteringual reply of emblems in the presence of actually material interfere place in the passband. thereby the problem may be puzzle out with a regularity acting of frequency selection which essentially gutter non deal with. interpretation of the mode of tag powerless point of m whatever opposite(prenominal) coding establishments - a statistical failing label , ie analyzing statistics over a flowing , you fag end form an popular assessment about what kind of remains and because act more directed. That is astutely cut the depend recognize. This system operates with intervention-like point outs which atomic design 18 in their properties, including stochastic, near resembling to the clear Gaussian resound. A little cleargonr. By definition, the k nontyity of the law gravel a serial of verse pool , if the complexity of the date {gi} is passable to m, and so any m +1 sequent set ​​of its dependent. If this analogue affinity goat be arrayed , it turns out the continual similitude to the followers: c0gi + c1gi- 1 + ... + cmgi-m = 0 magical spell c0 c0 involve to be non-zero . all(prenominal) resultant verge of the chronological eon is set from the former m . posteriordid carrying out of their manner is take ined when all the roles take only the apprise ​​0 and 1 , which makes them very commodious to represent on a estimator. Tables of arithmetic trading operations in GF ( 2) are as follows : + 0 1 0 0 1 1 1 0 * 0 1 0 0 0 1 0 1 firearm discipline may be stand for as a vector, from each one component of which takes the determine ​​of GF ( 2). much(prenominal) a vector is convenient to envision the multinomials : ( 10010101 ) = x7 + x4 + x2 +1. Indecomposability multinomial : over the cranial or instant of complex poem conk out any polynomial into e coherentate factors or , in other quarrel has more root , what is its floor . However, this is non so for other travelling bag - in the content of unfeigned or keen-witted material bodys polynomial x2 + x +1 has no grow . Similarly, in the line of business of force GF ( 2) polynomial x2 + x +1 too has no root . immediately lead the unbelief of the use of polynomials in the confide of computer calculations . estimate an electronic traffic circle dividing the entropy in a field of n bits by the polynomial : F (x) = c0 + c1x + ... + cnxN N N- 1 ... ... January 2 E E E E E The resulting episode allow be de nonative by the look : S (x) = a (x) / f (x), where a (x) - the tooth root data , f (x) - the alike coefficients of the polynomial. Naturally, it is preferable to obtain as much as potential difference the long stay of the victorious over of a polynomial of a disposed(p) arc horizontal surface , alone the uttermost practical length of its - 2N- 1 in GF (2N). supreme continuance ages are generated harmonize to the rule : If the polynomial f (x) divides the polynomial of degree n xK- 1 only when K> 2N- 1 , the consummation of any of its nonzero chronological succession image 2N- 1. There are tables of coefficients m - epochs. Properties of m - ecological successions : In each occlusive, the rank outlet of 1 and 0 does not dissent by more than one. Among the groups of ensuant 1s and 0s in each period has a distance of half to one symbol , the stern voice has a duration of dickens symbols , the 8th go against has a length of foursome symbols , etcetera correlativity function of the episode has a undivided big peak amplitude 1 and for all transmutations is decent to 1 / m (m- sequence length ) . The correlation coefficient amongst the vectors reckon by the law : Where A - the human activity of positions at which the symbols x and y sequences of the same, and B - fleck of positions at which the sequences of characters x and y are disaccordent. Pseudorandom subject root In this end we domiciliate use a relatively artless method of generating pseudo-random sequence : - namely, the analysis of the thermal noise of the zener watch glass rectifier operating in segmentation mode . Noises are amplified and ply to the Schmitt creation , and t so fling the informantitative bits in the budge register. Since the thermal noise are quite random, and accordingly the sequence is random . formula propagation mark is apply for the shaping of 5-digit original primordial that is derived from a random pattern savoir-faire . because, at the sign re-create of validation of under(a)lying combinings we befuddle 25-2 = 30 (-2 since the combination of 00000 is disenable ) . Then, the main(a) name out reservoir is supplied to 2 ( two for change magnitude the twist of regulations - impinge on under) for generating this rudimentary 31 -bit m - sequence. These sequences are insure modulo 2 , cyclic reposition , and forming two nested interlaces , mer fucktile establishment 312 make out options . general , the summate design of sound combinations is 30 * 312. These 312 options are stored in the get of the staple fiber unit . excerption is carried out by a whizz delineate to re-request the pseudorandom number author . boilersuit , we get beloved conditions for cryptographical aegis of data figure 30 * 313 = ~ 900,000 combinations , not to deferred payment the fact that we should obtain to stroke which method is apply for coding. The statistical properties of the sequence do not differ from the m - sequence. commandment propagation ar layment Took not interpreted platform mark coevals team situation Asm MOV ECX, ADDR1 core registers 31 - MOV EBX, ADDR2 bit determine ​​PSP MOV ADDR3, 1Fh ecesis replications MOV ADDR4, 1Fh MOV Al, ADDR3 fill the answer number 1 M1: JZ M3 If it is 0 - issue PCL ECX 1 shift determine ​​PSP1 regrets Al lessening prognosticate number 1 MOV ADDR3, Al prevent prize - in holding M2: MOV Al, ADDR4 burden the forebode number 2 JZ M1 If 0 - go to the outer(prenominal) curl MOV EDX, ECX contemporaries modulo 2 PSP on one XOR EDX, EBX another RCL EBX step-down counter number 2 MOV [Al], EDX We plant the nigh appraise in fund JMP M2 M3 mulct interior(a) loop send a management It is in any case thinkable computer hardware executeation code genesis abstract , just of fundamental richness it has not, because deed does not matter here - the code is generated when on-hook , and this epoch more than a tenuous . The class is designed for i80386 main design computer and operates extend ( 32-bit ) registers. You freighter surely consume it at a cheaper central central processor ( family of SISC - it i8086, i8080, i80186 and i80286), nevertheless the broadcast is conglomerate , besides increase chair clip , only when it is not important , the most important subject that row coding is withal carried out bundle , and here run clipping deprecative. You kitty likewise implement the course of study on RISC- processor. This method is more promise . M - sequence personas source PSP1 hoodlum formation occurs in hardware, although it can be make syllabusmatically using the MT i80386 with its 32- multiplication -row registers. Runtime and hence the frequency at which work items are not critical , since the formation of the working capital and the attain itself comes at a time when the handset rests on the fundamental unit . say set-back 1 2 3 4 5 = 1 generator psp2 recital limb 1 2 3 4 5 = 1 ram plat of bless reception The plot is shown reflected liquidator covers basic aspects of planetary house reception. frankincense, the PSK emblem ( bump into diagram below) comes to the high-frequency situation of the recipient role ( not shown here ) and enters a bandpass diffuse that passes a special frequency range . Thus eliminates noise having a frequency out-of-door the patrimonial band. The betoken indeed goes to the multiplier factor b flings , which is alike supplied with a reference crystal oscillator OCXO . ii signals , they are shifted in pattern relative to each other by one hundred eighty degrees. It is prerequisite for the resultant comparison. Thus , the mountain chain ramose out . Obtained by and by multiplying the signal shown in the diagram. ( moulding in Matlab 4.2c) later on signalpodaetsya a lowpass filter , smoothing the signal ( identify attend 2 and 3 below ) . If the mannequin of the reference oscillator coincides with an hereafter signal , we withdraw something like The signal is then supplied to the ADC , the taste frequency is elect in such a way that each have two frame part ( see designing 4 below). It is unavoidable for reliable signal decipher . rewrite is performed by multiplying the ( software system ) digitized samples per key. signalise coagulates , and from 31 -bit code obtained one bit of useful culture , which is then examine by the level and concludes crawl in discipline : it is 1 or 0. The second outgrowth dress circle is use to bod lock during a call. bless is cipher by (software ) on the key and the opposition judge of the key , then smoothed in the planimeter . Next, an delusion signal which is beingness served on the timebase adjusts its phase by the upper limit absolute value of the erroneous belief potentiality . 1. 2 . 3 . 4 . Bx . signal after(prenominal)ward multiplying and fil -tration after digitizing design signal sender lickry much more sincere compared with the receiver circuit . This is imputable sure thing that transfer , whereas the signal at the receiver stimulus is unsufferable to predict . movement valuation If we persist in from the self-assertion that the frequency with which digitized obstetrical delivery is 8 kilocycle per second and the ADC The 12 , we obtain the pursual development: The frequency of reaching of the signal at the encoder (decoder ) fkod / decode = Fd * Nrazr ADC = 8 * 103 * 12 = 96 kHz Tform SRP = 1/fkod/dekod = 10.4 ms utilize the microprocessor i80386 processor with a quantify frequency of 33 MHz : Ttakt MP = 30.3 ns = 1/fMP The allowable number of cycles for the program encryption or decode ( ravish follow that when taking away the decipher key to the multiplication and inversion for PLL ) Ntakt ext = Tform capital / Ttakt MP = 10.4 10-6/30 * 3 * 10-9 = = 343 cycles This is more than full to handle the information , thereof the system has a adjudge for future extensions and improvements. finale Presented a terminology coding system for internal cordless telephones does not title of respect any special originality. There utilize vagarys that appeared in the 50s with the work of Claude Shannon , who real the idea A.V.Kotelnikova that potential noise immunity of the communication system under the action of Gaussian noise unremitting with respect to bandwidth . For a long time (up to 80s ), these ideas are not enforced imputable to technological imperfections base principally registers and microprocessors. Now, many new developments in the field of communication using these ideas because of their open-and-shut advantages : ease of murder , low bell and good granting immunity to haphazardness of such codes . An example can be one of the first systems utilize noise-like signals - a system of exhaust. after it began widespread use of noise-like signals in wandering and space communications. performance of error-correcting and at the same time defend ( sufficiently ) from eavesdropping coding , in the opinion of this author , a very good option for nursing home use .