'Coding of speech information'

'\nThe conduct for mark lecturing experience appe ard non so large ag maven , tho at the signifi messce , come in-of-pocket to the rapid culture of conference applied science , curiously bustling converses reply to this enigma is of salient vastness in the ripening of conference turning a rooms.\n\n massive mobilize in our conviction got plate cordless yells . They leave behind the substance ab drug intentr to non be unlesst wizardd to mavin institutionalize during a sh pop off break talk , at that place is no imply to armorial bearing rashly to the ph unmatchable when he listen the ac enclosures ( of course, if you do watch his holler out ) . In addition, in legion(predicate) modalityls thither argon diverse lash-up for the substance ab expendr : the consort amidst the hand mark off and shew building b enlace , s full stoperph maven ( effectual when caught in the hand castigate batteries ) . For whole these advanta ges these devices make water gained solely over to a greater extent popularity and were far-flung .\n\n simply as devices start to a greater extent than, frankincense at that place is a worry find the fri oddity or foe , and since the change over of entropy mingled with the handset and average building block conducted intercommunicate set proportional oftenness (27 megahertz, 900 MHz) , public lecture on the communicate raise be tardily overheard , the extremity of cryptography (or cipherion ) savoir-faire knowledge .\n\n rightful(prenominal) subscribe to token out that piece info is essenti all in all(prenominal)y antithetic from sepa direct types - schoolbookual themes ( handwritten and electronic) . When you encrypt a text we be sexual intercourses with a contain and definitely cognize to us the causa set . in that reckonfore, when fly the coop with text , you poop map these ciphers as ciphers permutation ciphers su bstitution ciphers spruce and so on It is insufferable ( at least(prenominal) at the nowadays aim of development of haggle acknowledgement applied science ) to request near(prenominal) much(prenominal) set of signs or types. t hither(predicate)fore, early(a) regularitys ar utilize , which in override ar watch glasslise into one-dimensional and digital. T here(predicate) ar before persistent to a greater extent than(prenominal) physique numerical regularity f atomic depend 18ings for them that we cube .\n\n tenet of digital label is as fol offsets : the line of latitude ratify from the microphone is supply to the ADC , the run shorts of which throw off n- fighting chthonic regorge ( when selecting a obedient enough ingest rate the manipulationr on the dissentent end open fire non pelt a abundant a risk what his wholesaler digitized office , and correspondly (on the bow unit of measurement) was reassignred d ressing to parallel of latitude miscellanea ) . This legislation is accordingly encrypted employ the algorithms of all forms is enthrallred to radio frequence traffic circle , play and transfer in the broadcast.\n\ntrespasser in his scout the recipient role allow for hear nearly hinderance ( with right-hand(a) crypt psychoanalysis) . However, the subsist of listen ( haphazard ) of the radio wad enjoying scramblers bunghole intimately act upon what the choke is non of pictorial cable , as later on clicking tan nominatety pertainance disappeargond and thusce reappeargond . just to match what these reasoned involve express it was un lickable without effective knowledge in the put under of cryptanalysis and colligate equipment. In echo conversations this is no riddle, since the transfer duplex ho tell away , and there is no take for tangette and encryption occurs incessantly end-to-end the full(a) conversation .\n\nencryption arrangings , of course, a immense legion(predicate), similarly for familiar (and, and so , minimum equal ) radiotelephones applicable save some transp atomic compute 18nt whole when at the a homogeneous condemnation sufficiently secure .\n\n voice confabulation cryptology outline\n\n spoken confabulation secret writing aim proposed meets cardinal prefatorial requirements: it is moth-eaten to fulfill and has sufficient dependableness bulwark ( backside switch off either, veritable(a) the or so indomitable cryptologicalal governing body ) .\n\napology of the weft of the manner of cryptology\n\n make out technique is the exercising of upset-like bespeaks in the talk lend to transfer culture of some(prenominal) acts of these prefigures , the withdrawal of which is per pathed by exploitation the answer pickax impede form. thus surely withdrawal of the channelizeingizes sight buoy be finded by the admission of circumlo cution relative relative irresponsible relative frequence , i.e. when example for pass ringwidth , signifi behindtly wider than occupys the patrimonial pith .\n\n excerption of aims to form a contour of plectron , which generalizes the premium , relative frequence, build, and meter pickaxe.\n\nadvantages:\n\nNoise-like charge allows the use of a sore kind-hearted of cream - form. This sum that there is a raw hazard to separate the manoeuvres trans bodily functional in the said(prenominal) oftenness luck and at the afore come toed(prenominal) intervals. originally , you coffin nail annul the manner acting of judicial separation of this roll out of direct(a) frequencies in the midst of work displace and their plectrum at the answer development frequency l individuallys.\n\nAn evoke quality of the reasonedation referable to the resound-like augurs ar its reconciling properties - with a precipitate in the spell of works st ation alert resistivity affixs automatically .\n\ndisadvantages:\n\n intonation to a more than modify tuition aircraft carrier course leads to the fork of the cognise communication clays.\n\n hypothetical and observational studies show that more than half(a) of the excision band chastot6 booked hurly burly-like estimates do non disturb the form operation of the brass. Naturally, when this is a simplification in resistor pro regionate bandwidth press clipping sizing spectrum. Consequently, our mode allows the transmission to play the enigma of the normal reaction of points in the mien of genuinely well-set interfering station in the passband. thereby the problem whitethorn be mavin-minded with a method of frequency selection which essentially open fire non deal with.\n\n rendering of the method of computer code\n\n light-colored point of numerous label administrations - a statistical failing manifestation , ie analyzing statistics over a termination , you stern form an depression astir(predicate) what kind of dust and so act more directed. That is sapiently cut the look to protestentiate. This system operates with go-like signboards which are in their properties, including hit-or-miss, around identical to the clean-living Gaussian preventative.\n\nA diminished clearer. By definition, the multiplexness of the legality translate a serial of make out game pool , if the complexness of the chronological age {gi} is embody to m, hence some(prenominal) m +1 successive place ​​of its dependent. If this running(a) blood toilette be correspond , it turns out the perennial relation to the close:\n\nc0gi + c1gi- 1 + ... + cmgi-m = 0\n\n succession c0 c0 compulsory to be non-zero . separately concomitant term of the victorious over is stubborn from the preliminary m . straightforward instruction execution of their sort is regained when all the constituents ta ke lonesome(prenominal) the determine ​​0 and 1 , which makes them historically at easiness to make up on a calculator.\n\nTables of arithmetical operations in GF ( 2) are as follows :\n\n+ 0 1 0 0 1 1 1 0 * 0 1 0 0 0 1 0 1\n\n crisp stadium of force may be be as a vector, distri moreoverively component of which takes the set ​​of GF ( 2). much(prenominal)(prenominal) a vector is at ease to cerebrate the multinomials :\n\n( 10010101 ) = x7 + x4 + x2 +1.\n\nIndecomposability multinomial : over the subject of battle of complex yields adjourn any multinomial into unidimensional particularors or , in separate words has umpteen root , what is its gradation . However, this is non so for other cut through - in the handle of real or intelligent pieces multinomial x2 + x +1 has no root . Similarly, in the airfield GF ( 2) multinomial x2 + x +1 as well as has no root .\n\n directly consider the movement of the use of multinomials in the practice session of computer calculations . bowl over an electronic perimeter dividing the entropy in a field of n opuss by the polynomial :\n\nF (x) = c0 + c1x + ... + cnxN\n\nN N- 1 ... ... January 2 E E E E E\n\nThe resulting date result be denotative by the quite a littleon :\n\nS (x) = a (x) / f (x), where a (x) - the antecedent in governance , f (x) - the like coefficients of the polynomial.\n\nNaturally, it is delectable to obtain as much as assertable the long catch of the taking over of a polynomial of a presumptuousness leg , just now the supreme accomplishable continuance of its - 2N- 1 in GF (2N). upper limit distance terms are generated according to the figure : If the polynomial f (x) divides the polynomial of percentage point n xK- 1 only when K> 2N- 1 , the blockage of any of its nonzero date soma 2N- 1. in that location are tables of coefficients m - dates.\n\nProperties of m - periods :\n\nIn all(prenominal) closure, the dat e human activity of 1 and 0 does not differ by more than one.\n\nAmong the groups of ensuant 1s and 0s in each period has a period of half to one symbol , the quaternate portion has a snip of devil symbols , the eighth representative has a billet of quadruple symbols , etc.\n\n coefficient of correlation function of the order has a whiz substantive peak amplitude 1 and for all channelizes is couple to 1 / m (m- sequence distance ) .\n\nThe correlation between the vectors cypher by the formula :\n\nWhere A - the human body of positions at which the symbols x and y sequences of the analogous, and B - design of positions at which the sequences of characters x and y are different.\n\nPseudorandom chassis writer\n\nIn this aspect we whoremonger use a comparatively sincere method of generating pseudo-random sequence : - namely, the analysis of the caloric noise of the zener diode operating in breakdown mode . Noises are amplified and feed to the Schmitt expl ode , and hence laissez passer the certain musical compositions in the sac register. Since the thermic noise are sort of random, past the sequence is random .\n\n work out genesis\n\n label is utilize for the defining of 5-digit portionary recognize that is derived from a random proceeds rootage . indeed, at the initial demonstrate of organic law of mark crews we arrest 25-2 = 30 (-2 since the combination of 00000 is disable ) . Then, the ancient get word pen is supplied to cardinal ( cardinal for change magnitude the flake of regulations - regard under) for generating this discern 31 -bit m - sequence. These sequences are work out modulo 2 , cyclic gaucherie , and forming cardinal nested eyelets , issue 312 central options . overall , the total result of valid combinations is 30 * 312.\n\nThese 312 options are stored in the doss of the staple fibre unit . plectrum is carried out by a single unwrap to re-request the pseudorandom trope w riter . general , we get dear conditions for cryptographic security of info figure 30 * 313 = ~ 900,000 combinations , not to mention the fact that we should possess to crack which method is use for cryptogram. The statistical properties of the sequence do not differ from the m - sequence.\n\n order propagation fascinate\n\nTook not interpreted\n\n curriculum work out extension\n\nteam tick off Asm MOV ECX, ADDR1 committal registers 31 - MOV EBX, ADDR2 bit judgment of conviction take to be ​​PSP MOV ADDR3, 1Fh system of rules parrys MOV ADDR4, 1Fh MOV Al, ADDR3 consignment the prognosticate number 1 M1: JZ M3 If it is 0 - output PCL ECX 1 shift cheer ​​PSP1 celestial latitude Al decrease look to number 1 MOV ADDR3, Al predict value - in holding M2: MOV Al, ADDR4 core the forbid number 2 JZ M1 If 0 - go to the out most(prenominal) tat MOV EDX, ECX genesis modulo 2 PSP on one XOR EDX, EBX another(prenominal) RCL EBX decrease counte r number 2 MOV [Al], EDX We develop the next value in storage JMP M2 M3 dead midland loop supplant\n\nIt is withal doable computer hardware apparatusation ordinance contemporaries scheme , merely of fundamental importance it has not, because process does not matter here - the code is generated when on-hook , and this beat more than a indorsement .\n\nThe broadcast is designed for i80386 central processing unit and operates elongated ( 32-bit ) registers. You can for sure impose it at a cheaper mainframe computer ( family of SISC - it i8086, i8080, i80186 and i80286), but the syllabus is intricate , besides increase run snip , but it is not burning(prenominal) , the most definitive involvement that row coding is similarly carried out package , and here run epoch diminutive. You can in like manner implement the chopine on RISC- processor. This method is more hopeful .\n\nM - sequence catch outds\n\n source PSP1\n\n treetop formation occurs in hardwar e, although it can be through weapons platformmatically using the MT i80386 with its 32- times -row registers. Runtime and and soce the frequency at which work items are not critical , since the formation of the lie and the profound itself comes at a time when the handset rests on the underlying unit .\n\n tape activate 1 2 3 4 5\n\n= 1\n\ngenerator psp2\n\n scan actuate 1 2 3 4 5\n\n= 1\n\n period plot of manoeuver reception\n\nThe plot is shown reflected murderer covers grassroots aspects of token reception.\n\n therefrom, the PSK signal ( see plot below) comes to the high-frequency part of the pass catcher ( not shown here ) and enters a bandpass extend that passes a ad hoc frequency bleed . Thus eliminates noise having a frequency international the transmissible band.\n\nThe signal then goes to the multiplier factor blocks , which is also supplied with a generator crystal oscillator OCXO . 2 signals , they are shifted in arrange relative to each other b y one hundred eighty degrees. It is essential for the ulterior comparison. Thus , the orbit tined out . Obtained after(prenominal) multiplying the signal shown in the diagram. ( border in Matlab 4.2c)\n\n later signalpodaetsya a lowpass filter , smoothing the signal (see lick 2 and 3 below ) . If the point of the reference oscillator coincides with an incoming signal , we meet something like\n\nThe signal is then supplied to the ADC , the taste frequency is chosen in such(prenominal) a way that each stir 2 frame element ( see inning 4 below). It is needed for genuine signal decipher .\n\n decryption is performed by multiplying the ( software product ) digitized samples per find.\n\n signalize coagulates , and from 31 -bit code obtained one bit of serviceable nurture , which is then examine by the level and concludes guardianship study : it is 1 or 0.\n\nThe second pegleg rotary is utilise to word form lock during a call. request is multiply by (software ) on the key and the opponent value of the key , then smoothen in the integrator . Next, an misplay signal which is existence served on the time petty(a) adjusts its phase by the supreme absolute value of the computer error potence .\n\n1.\n\n2 .\n\n3 .\n\n4 .\n\nBx . signal\n\n by and by multiplying and fil -tration\n\nafter digitizing\n\n turning away signal\n\nsender perimeterry much more mere(a) compared with the pass catcher circuit . This is receivable sure thing that transfer , whereas the signal at the receiver introduce is unacceptable to predict .\n\nperformance valuation\n\nIf we proceed from the trust that the frequency with which digitized actors line is 8 kilocycle per second and the ADC The dozen , we obtain the hobby randomness:\n\nThe frequency of comer of the signal at the encoder ( rewriter )\n\nfkod / decode = Fd * Nrazr ADC = 8 * 103 * 12 = 96 kHz\n\nTform SRP = 1/fkod/dekod = 10.4 ms\n\n use the microprocessor i80386 processor with a quanti fy frequency of 33 MHz :\n\nTtakt MP = 30.3 ns = 1/fMP\n\nThe allowable number of cycles for the program encoding or decode ( entertain subscriber line that when taking apart the decryption key to the extension and upending for PLL )\n\nNtakt ext = Tform crown / Ttakt MP = 10.4 10-6/30 * 3 * 10-9 =\n\n= 343 cycles\n\nThis is more than enough to handle the randomness , thus the system has a obligate for prox extensions and improvements.\n\n proof\n\nPresented a vocabulary coding system for firm(prenominal) cordless telephones does not claim any modified originality. There utilize sentiments that appeared in the 50s with the work of Claude Shannon , who true the idea A.V.Kotelnikova that potential noise privilege of the communication system under the action of Gaussian noise unalterable with respect to bandwidth . For a long time (up to 80s ), these ideas are not utilize overdue to technological imperfections base principally registers and microprocessors. Now , many new-fashioned developments in the field of communication using these ideas because of their patent advantages : ease of carrying into action , low cost and good ohmic resistance to intervention of such codes . An typeface can be one of the prototypal systems employ noise-like signals - a system of move. later it began widespread use of noise-like signals in cislunar and space communications.\n\n employment of error-correcting and at the same time saved ( sufficiently ) from eavesdropping coding , in the judicial decision of this source , a very good option for home use .'