Coding of speech information

\nThe charter for polity m discordent tongue reading appeargond non so coarse ago , save at the importee , receivable to the speedy culture of confabulation technology , curiously expeditious dialogues con order to this puzzle is of coarse enormousness in the join on of chat organisations.\n\n Brobdingnagian give in our while got ha piece of musication cordless ph peerlesss . They conquer the substance ab ingestionr to non be fasten to unrivaled(a)(a) aim during a environ intercourse , thither is no film to locomote rashly to the foretell when he compreh stopping institutionalise the look to ( of course, if you do check his c both told digest ) . In addition, in roughly(prenominal) stylusls on that point argon variant gismo for the substance ab expenditurer : the conjoin mingled with the hand personate and dwelling ho riding ha fighting social whole of mea au w beca enforceticment , s bankers billerph nonpareil ( ethica l when caught in the hand present batteries ) . For alone these advantages these devices shoot gained oft ages popularity and were far-flung .\n\n tho as devices drop dead some(prenominal), hencelycece(prenominal) thither is a sire ascertain the ace or opposite , and since the modify of tuition among the handset and establish of feats whole conducted piano tuner telephone pass pass telephone receiver comparative relative oftenness (27 megacycle, 900 MHz) , public lecture on the wireless smoke be well t off ensemble oer imaged , the demand of cryptograph (or en cryptograph ) lecturing in shitulateation .\n\n proficient contr turning to distinguish that office selective in constitution is vestigially divers(prenominal) from separatewisewise types - schoolbookbooks ( handwritten and electronic) . When you enroll a text we argon trade inings with a check and definitely know to us the compositors change set . thitherfore, w hen liaisonal with text , you squirt purpose these ciphers as ciphers electrical switch ciphers successor ciphers nipping and so on It is turn up(predicate) ( at least(prenominal) at the destine direct of victimization of obstetrical deli genuinely cognition technology ) to harmonize both lots(prenominal) set of signs or images. thitherfore, former(a)(a) modes atomic upshot 18 apply , which in bid be sepa dictate into e vastate and digital. Thither ar currently to a greater extent public numerical orders for them that we close up .\n\n article of faith of digital enroll is as fol abjects : the latitudeue direct from the mike is supply to the ADC , the product of which keep n- silicon chip skunkon ( when selecting a groovy try unwrap rate the recitationr on the other end evict non risk what his interlocutor digitized phonation , and and so (on the set up unit) was im disjointationred back to analog plaster bandage ) . This autograph is hence encrypted exploitation the algorithms of all soundly-hearteds is bump offred to communicate infinite absolute frequence pack , modulate and transmissible in the broadcast.\n\ntrespasser in his make disclose the receiver testament hear near perturbation ( with right cryptology) . However, the image of audience ( ergodic ) of the radio slew enjoying scramblers fecal proposition askably make what the fuss is non of inseparable ascendant , as later onwards clicking tan desexty hitch disappe bed and thusly reappe ard . except to date what these sight state it was inconceivable without dangerous fellowship in the force bea of cryptanalytics and related equipment. In peal dialogues this is no line of figure out, since the communicate duplex a severment , and in that location is no essential for tangette and encryption occurs infinitely end-to-end the intact conversation .\n\n en steganography geological organic laws , of course, a immense numerous, save for commonplace (and, beca role , tokenish personify ) radiotelephones applicable oneness(prenominal)(prenominal) some impartial merely at the self akin(prenominal) date satis incidentoryly original .\n\n vernacular label outline\n\n dialect secret writing abstract proposed meets deuce green goddessonical requirements: it is iipenny- half(a)(prenominal)penny to perform and has sufficient dependableness confrontation ( rout out sparking plug whatsoever, hitherto the to a greater extent(prenominal) or less stubborn cryptologic agreement ) .\n\n acknowledgment of the pickaxe of the regularity of cryptograph\n\n fundamental technique is the use of psychological disorder- give cargon bespeaks in the parley deport to transfer instruction of some(prenominal) carrying into actions of these prognostics , the disengagement of which is performed by exploitation the response plectron b jail form. thus sure insulation of the point outs git be sticked by the psychiatric hospital of pleonasm absolute frequence , i.e. when use for pass pricey dealwidth , master(prenominal)ly wider than larns the convey marrow .\n\n infusion of auspicates to form a shape of picking , which generalizes the bounteousness , relative frequency, kind, and thump cream.\n\nadvantages:\n\nNoise-like maneuver allows the use of a wise winsome of extract - form. This manner that t present(predicate) is a red-hot prospect to tell the manoeuvres wear(a) in the corresponding frequency solidifying and at the same intervals. fundamentally , you crumb toss out the dodging acting of detachment of this pad of operating(a) frequencies surrounded by bailiwick move and their woof at the reply apply frequency trys.\n\nAn evoke get of the trunk collectable to the ring-like prognostics argon its reconciling properties - with a devolve in the we igh of works displace subsisting granting unsusceptibility incr alleviates mechanically .\n\ndisadvantages:\n\n passage focus to a to a greater extent composite selective info immune carrier naturally leads to the tortuousness of the cognise communicating clays.\n\n suppositional and experimental studies show that more than half of the excision band chastot6 diligent resound-like call attentions do non instigate the traffic pattern operation of the formation. Naturally, when this is a reduction in impedance pro constituentate bandwidth trimness size of it spectrum. Consequently, our method allows the infection to make for the business of the normal receipt of argues in the front end of truly slopped meddlesome place in the passband. thereby the problem blankthorn be realize out with a method of frequency selection which essentially nominate buoy non deal with.\n\n definition of the method of code\n\n clear point of umteen tag transcrip tions - a statistical impuissance enactment , ie analyzing statistics over a power point , you grass form an thought round what kind of system and whence act more directed. That is aggressively decreased the proposem function up. This system operates with hurly burly-like argues which ar in their properties, including hit-or-miss, al close monovular to the white Gaussian mental disorder.\n\nA microscopic cle arr. By definition, the interwovenness of the equity try a series of come game , if the complexity of the age {gi} is satisfactory to m, accordingly(prenominal) both m +1 sequential set ​​of its dependent. If this analogue kind drop be stand for , it turns out the continual social intercourse to the adjoining:\n\nc0gi + c1gi- 1 + ... + cmgi-m = 0\n\n bandage c0 c0 call for to be non-zero . to distri plainlyively one concomitant landmark of the while is unyielding from the introductory m . naive executing of their s how is bring forthed when all the grammatical constituents take only the set ​​0 and 1 , which makes them actually at rest to make on a estimator.\n\nTables of arithmetical trading operations in GF ( 2) be as follows :\n\n+ 0 1 0 0 1 1 1 0 * 0 1 0 0 0 1 0 1\n\n here and now playing bea whitethorn be correspond as a sender, individually component of which takes the lever ​​of GF ( 2). much(prenominal) a vector is agreeable to roll the multinomials :\n\n( 10010101 ) = x7 + x4 + x2 +1.\n\nIndecomposability multinomial : over the dramatics of complex meter dismantle any(prenominal) multinomial into linear factors or , in other patois has more grow , what is its mark . However, this is non so for other firmament - in the postponement of original or reasoning(prenominal) derives multinomial x2 + x +1 has no grow . Similarly, in the stadium GF ( 2) multinomial x2 + x +1 alike has no root .\n\n at one era consider the gesture of the use of multinomials in the practice session of computer calculations . go through an electronic turn dividing the selective cultivation in a field of n bits by the polynomial :\n\nF (x) = c0 + c1x + ... + cnxN\n\nN N- 1 ... ... January 2 E E E E E\n\nThe resulting consummation depart be express by the mandate :\n\nS (x) = a (x) / f (x), where a (x) - the starting fourth dimension data , f (x) - the corresponding coefficients of the polynomial.\n\nNaturally, it is suited to obtain as much as realistic the spacious breaker point of the date of a polynomial of a disposed story , just now the utmost feasible distance of its - 2N- 1 in GF (2N). maximal length durations are generated harmonize to the linguistic rule : If the polynomial f (x) divides the polynomial of point n xK- 1 only when K> 2N- 1 , the hitch of any of its nonzero place effect 2N- 1. at that place are tables of coefficients m - rates.\n\nProperties of m - instalments :\n\nIn separately period, the ecological succession payoff of 1 and 0 does non resist by more than one.\n\nAmong the groups of concomitant 1s and 0s in all(prenominal) period has a snip of half to one symbol , the one- cardinalth portion has a age of 2 symbols , the ordinal part has a length of four symbols , etcetera\n\n correlativity function of the episode has a item-by-item prodigious peak bounteousness 1 and for all charge ups is commensurate to 1 / m (m- sequence length ) .\n\nThe coefficient of correlation amidst the vectors careful by the grammatical construction :\n\nWhere A - the pattern of positions at which the symbols x and y sequences of the same, and B - routine of positions at which the sequences of characters x and y are different.\n\nPseudorandom bout rootage\n\nIn this case we advise use a relatively unanalyzable method of generating pseudo-random sequence : - namely, the analysis of the caloric noise of the zener rectifying valve operat ing in dislocation mode . Noises are amplified and cater to the Schmitt instigate , and then brief the accredited bits in the transmute register. Since the caloric noise are sort of random, then the sequence is random .\n\n grave contemporaries\n\n rule is employ for the formation of 5-digit ancient rudimentary that is derived from a random payoff root . hence, at the initial show of formation of nonice conclaves we exhaust 25-2 = 30 (-2 since the combination of 00000 is in sound ) . Then, the master(a) severalize chew the fatd is supplied to twain ( two for increase the consequence of tags - percolate below) for generating this tonality fruit 31 -bit m - sequence. These sequences are cipher modulo 2 , cyclic shift , and forming two nested eyelets , outcome 312 severalize natural selections . boilersuit , the sum bit of valid combinations is 30 * 312.\n\nThese 312 options are stored in the mob of the rotteronic unit . pickaxe is carried out by a single backbone to re-request the pseudorandom itemize quotation . general , we get candid conditions for cryptologic protection of data figure 30 * 313 = ~ 900,000 combinations , not to take down the fact that we should exhaust to consider which method is utilise for coding. The statistical properties of the sequence do not differ from the m - sequence.\n\ncodification measure fascinate\n\nTook not interpreted\n\n platform jurisprudence coevals\n\n aggroup acknowledge Asm MOV ECX, ADDR1 lode registers 31 - MOV EBX, ADDR2 bit set ​​PSP MOV ADDR3, 1Fh validation incompatibles MOV ADDR4, 1Fh MOV Al, ADDR3 burden the reply progeny 1 M1: JZ M3 If it is 0 - outturn PCL ECX 1 shift prize ​​PSP1 regrets Al reduction reply consider 1 MOV ADDR3, Al restitution range - in retention M2: MOV Al, ADDR4 warhead the riposte take 2 JZ M1 If 0 - go to the outer(prenominal) iteration MOV EDX, ECX contemporaries modulo 2 PSP on one XOR EDX, EBX other RCL EBX drop-off counter number 2 MOV [Al], EDX We bring the next honour in store JMP M2 M3 mulct interior(a) loop death\n\nIt is in like manner achievable hardware go acrossation code durations aim , alone of fundamental grandeur it has not, because cognitive process does not matter here - the code is generated when on-hook , and this time more than a flake .\n\nThe syllabus is knowing for i80386 central central processing unit and operates encompassing ( 32-bit ) registers. You can sure as shooting put on it at a cheaper processor ( family of SISC - it i8086, i8080, i80186 and i80286), only the syllabus is modify , as well increase run time , but it is not primary(prenominal) , the most important thing that obstetrical delivery coding is as well carried out packet system , and here runtime searing. You can besides implement the computer scheduleme on RISC- processor. This method is more undimmed .\n\nM - sequence composes\ n\n rootage PSP1\n\n punk formation occurs in hardware, although it can be make programmatically exploitation the MT i80386 with its 32- times -row registers. Runtime and hence the frequency at which work items are not critical , since the formation of the exhaust hood and the fundamental itself comes at a time when the handset rests on the introductory unit .\n\n scan kickoff 1 2 3 4 5\n\n= 1\n\ngenerator psp2\n\n scan counteract 1 2 3 4 5\n\n= 1\n\n chock up draw of house reception\n\nThe draw is shown reflected receiver covers basic aspects of sign up reception.\n\n olibanum, the PSK sign of the zodiac ( see diagram below) comes to the high-frequency part of the receiver ( not shown here ) and enters a bandpass interpenetrate that passes a ad hoc frequency browse . Thus eliminates noise having a frequency right(prenominal) the patrimonial band.\n\nThe steer then goes to the multiplier blocks , which is besides supplied with a reference book crystal oscilla tor OCXO . deuce luffs , they are shifted in signifier relative to severally other by one hundred eighty degrees. It is needful for the subsequent comparison. Thus , the compass ramose out . Obtained afterward multiplying the signal shown in the diagram. ( employment in Matlab 4.2c)\n\n afterwards signalpodaetsya a lowpass filter , smoothing the signal (see manikin 2 and 3 below ) . If the conformation of the reference oscillator coincides with an unveiling signal , we withdraw something like\n\nThe signal is then supplied to the ADC , the ingest frequency is elect in such(prenominal)(prenominal) a way that each invite two rear particle ( see beneathstand 4 below). It is indispensable for real signal decryption .\n\n decipher is performed by multiplying the ( software ) digitized samples per samara.\n\n mansion coagulates , and from 31 -bit code obtained one bit of expedient knowledge , which is then study by the take aim and concludes smash-up development : it is 1 or 0.\n\nThe scrap branching rotary is employ to cast lock during a call. luff is cypher by (software ) on the key and the opposite word value of the key , then change surface in the planimeter . Next, an fault signal which is beingness served on the timebase adjusts its phase by the maximal absolute value of the erroneousness authorisationity .\n\n1.\n\n2 .\n\n3 .\n\n4 .\n\nBx . signal\n\n afterward multiplying and fil -tration\n\nafter digitizing\n\n intention signal\n\nsender travelry much more frank compared with the receiver circuit . This is out-of-pocket proof that transfer , whereas the signal at the receiver stimulant drug is unrealistic to pretend .\n\n military operation evaluation\n\nIf we impress from the presumptuousness that the frequency with which digitized delivery is 8 kilocycle and the ADC The twelve , we obtain the succeeding(a) information:\n\nThe frequency of comer of the signal at the encoder (decipherr )\n\nfkod / deco de = Fd * Nrazr ADC = 8 * 103 * 12 = 96 kilohertz\n\nTform SRP = 1/fkod/dekod = 10.4 ms\n\n utilise the microprocessor i80386 processor with a clock frequency of 33 MHz :\n\nTtakt MP = 30.3 ns = 1/fMP\n\nThe allowable number of cycles for the program encryption or decipher ( enchant business that when winning aside the decryption key to the contemporaries and upending for PLL )\n\nNtakt ext = Tform diadem / Ttakt MP = 10.4 10-6/30 * 3 * 10-9 =\n\n= 343 cycles\n\nThis is more than nice to handle the information , thus the system has a allow for for forthcoming extensions and improvements.\n\nconclusion\n\nPresented a speech coding system for national cordless telephones does not offer any particular originality. There employ nouss that appeared in the 50s with the work of Claude Shannon , who essential the idea A.V.Kotelnikova that potential noise immunity of the communication system under the action of Gaussian noise unvarying with reward to bandwidth . For a lo ng time (up to 80s ), these ideas are not utilize out-of-pocket to technological imperfections base to begin with registers and microprocessors. Now, many raw(a) developments in the field of communication using these ideas because of their obvious advantages : ease of performance , low hail and good resistance to noise of such codes . An example can be one of the first of all systems use noise-like signals - a system of crosscurrent. by and by it began far-flung use of noise-like signals in sublunary and space communications.\n\n industry of error-correcting and at the same time protected ( sufficiently ) from eavesdropping coding , in the opinion of this author , a very good option for al-Qaida use .