SU934891A1 - Device for digital group generation of sinusoidal signals - Google Patents

Abstract

1. USTRS) FOR DIGITAL GROUP GENERATION OF SINUSOIP-ALNY SIGNALS, containing 1 Digital oscillators of the lowest frequency. and difference frequency, characterized in that, in order to suppress the g / device by minimizing the frequency of digital generators, it contains (N-1) identical digital mixers connected in cascade, with the quadrature outputs of the lowest-frequency digital generator the mixer, the quadrature outputs of the digital differential frequency generator are connected in parallel to the inputs of all digital mixers, and the quadrature outputs of these mixers and the quadrature outputs of the digital generator are Your frequencies are tied to the device's output buses. with H tf.-i «J (L

Description

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2. Usgruzgvo according to Clause 1, about tl p h a - I you shema with heme, each digital gel mixture contains four multipliers, two adders and a sign inverter, and the inputs of the first and second multiply networks are connected to the cosine output of the previous mixer , and the inputs of the third and fourth multipliers are connected to the sine output of the previous mixer, the cosine output of the differential frequency generator is connected to the inputs of the first, and the invention relates to a technique of digital signal processing in specialized computing devices ISPS zovani multichannel transmission systems signalov5 communication with frequencies seal employing digital processing of these signals to the terminal devices.

The known carrier group generator used in the 12-kanapu Yu-equipment of the frequency seal of telephone signals 1 J, In this generator contains a high-speed digital generator of a pair of signals cosoipt sin LVp t, which operates in a multi-15 Plex mode. During the k - th clock interval auxiliary4

the block generates the values of 12 phases .T (xi {p 1 ,, .., 12) and 12 times sequentially refers to the individual generator block 20 to calculate the values of the counts 4, Sin f,. Thus, the digital generator block is used with a clock frequency of 12 f

The disadvantage of such a generator is 25 b of the need to use a high clock frequency, which is N times the frequency of access to the device, and the associated complexity of the device.

The purpose of the invention is to simplify the device ZO SGESH by minimizing the clock frequency of digital generators,

The device is achieved by the fact that the device is given a digital group generation of sinusodal signals, which contains digital low frequency and differential frequency generators 35, also contains (N - 1) identical digital mixers, connected in cascade, with the quadrature outputs of the lowest frequency generator 40

891

the second multiplier, the sine output of the differential frequency generator are connected to the inputs of the second and fourth multipliers, the outputs of the second and third multipliers are connected to the inputs of the sine adder, the output of the first multiplier is directly connected, and the output of the fourth multiplier is connected to the inputs of the cosine adder, and the outputs of the sine adders and cosine serve as the corresponding outputs of the mixer.

connected to the inputs of the first digital mixer, the quadrature outputs of the digital differential frequency generator are connected in parallel to the inputs of all digital mixers, and the quadrature outputs of these mixers and the quadrature outputs of the digital generator of the lowest frequency are connected to the output widths of the device.

In addition, each digital mixer contains four multipliers, two adders and a sign inverter, the inputs of the first and second multipliers are connected to the cosine output of the previous mixer, and the inputs of the third and fourth multipliers are connected to the sinus output of the previous mixer, the cosine output of the differential frequency generator is associated the inputs of the first and third multipliers, the sinus output of the differential frequency generator is connected to the inputs of the second and fourth multipliers, the outputs of the second and third multipliers are connected to odes adder sine output of the first multiplier directly and the output of the fourth multiplier via an inverter atsaka coupled to inputs of the adder cosine, and outputs sine and cosine adders are respective outputs of the mixer.

FIG. 1 shows a block diagram of a device for digitally generating a group of sinusoidal signals, FIG. 2 is a block diagram of a digital mixer.

The device contains a digital generator 1 of the lowest frequency p, podtyuchenny to the inputs of the first of (N -1) digital mixers 2, 2 || . connected interchangeably, the second inputs of the digital mixers are connected to the outputs of the digital generator 3 of the upper frequency range, the output of the lowest frequency generator and the outputs of the mixers are connected to the output buses of the device 4 4. , Each digital mixer contains four multipliers 5-8, two adders 9.1O and an inverter 11 characters, with inputs of multipliers 5 and 6 connected to the cosine output of the previous signal source, which may be a previous ST1FORMER or least frequency generator, inputs of multipliers 7 and 8 are connected to the sine output of the previous source, the cosine output of the differential frequency generator 3 is connected to the inputs of multipliers 5 and 7, the sine output of the generator 3 is connected to the inputs of multipliers 6 and B, the outputs of multipliers 6 and 7 are connected to su inputs The mmator 10, the output of the multiplier 5 are directly, and the output of the multiplier 8 is connected via inverter 11 to the inputs of the adder 9. The device generates sinusoidal signals whose frequencies are evenly distributed along the frequency axis, forming the main pairs of samples (codes) (oos 2TiF kT. 5in27 / F 1 Tj and (SOz 2. Fp x G, Sin glRp1 and at any time using two individual digital generators 1 and 3, and the pair of readings (cos, sin 27 L F kTJBcex are the rest of the frequencies Fp, starting from the second, are obtained by recursion frequency when mixing samples of the previous frequency FP - I and difference frequency l F with the help of (N -1) identical blocks of digital mixers 2 -2 The beginning of the k-th clock interval kT is set by an external pulse generator. gakgovoy frequency g,. The generator 1 of the smallest frequency produces a pair of samples of cos 2, 5 ,, Si p, generator 3 gives a couple of counts оС1с С05 27GlR1 T, Ibti sin2 aF-kr. Generators 1 and 3 are required to generate an unbounded sequence of samples of sinusoidal signals without accumulating computational errors and observing the necessary spectrum purity. In particular, this type of generator may include a permanent storage device containing a table of sines and cosines. When working with the lowest clock frequency f, the number of these generators cannot be less than two, since the frequencies P and 4 F are independent and are set as arbitrary parameters that determine the structure of the device as a whole. In multipliers 5-8 p-th mixer are formed signals, respectively, equal to C0527rFpkT C052LLR T; cos 2JRr KG sin 2LLR1 T; Sin 2J / Pp1 T cos 21G4R1 T; 5i 27rPp1 Г-S1пгллPkT. On the outputs of the adders 9 and 1O F-ro of the mixer (taking into account the inverter 11), codes (Рр4ЛР Т со52; 7Рр 1КТ;,) Т.51п2ЛррМКТ are formed, which are counts of the frequency Fp4-i at the clock time kT. Thus, each digital mixer recurses in frequency for a fixed time. Received in the generator 1 and mixers 2-1 - 2 samples (codes Ср 1 Sp ,, N) arrive at the outputs of the device in the form of N quadrature pairs of sinusoidal signals with frequencies P-1 |.,. P at a given clock .moment kT. When a chain of digital mixers 2-2 is operating, there is a time delay, which in the case of simultaneous synchrony and synphase, ,, 1k 1 output signals (C ,. 5 (C | M1 can be eliminated either by introducing elements of the backplane on the time (N –p) T in the output signal chain (Spx) of each p-th mixer, or by increasing the clock frequency controlling the operation of the mixers in N j5a3, so that in one clock interval T would fit (N -1) successive recursion operations in a chain of digital mixers. Go, in the process of multiplying and adding in mixers, the inconsistency of the original signals increases (Cj, and the number of correct binary digits in the output codes can be reduced by V + 1, where (B then to achieve the required purity of the spectrum at the output of the mixer, the code depth; in the internal circuits of the mixers must be increased by V + 1,

The proposed device for digital ((group generation of sinusoidal sig: 0 / lg

This allows us to minimize the number of individual frequency generation operations and heme the most simplify the equipment used while maintaining the required quality indicators.

Claims (2)

1. APPARATUS FOR GENERATING DIGITAL GROUP ^T SR sine catch comprising digital generators least chastotal and difference frequencies, characterized in that, in order to simplify the device by minimizing the clock frequency of digital generators, it comprises (N-1) of the same digital mixers connected in cascade moreover, the quadrature outputs of the digital generator of the lowest frequency are connected to the inputs of the first digital mixer, the quadrature outputs of the digital generator of the differential frequency are connected in parallel to the inputs of ex digital mixers, and quadrature outputs of the mixers and quadrature digital outputs of the lowest frequency generator associated with the output device buses. SU „934891 '33 4891 2. Device according to claim 1 of m and n and h - ¹ w o f e c i in that each digital mixer comprises four multipliers, two adders, and a sign inverter, wherein the first and second inputs of the multipliers are connected to the output of the preceding cosine mixer and the inputs of the third and fourth multipliers are connected to the sine output of the previous mixer, the cosine output of the difference frequency generator is connected to the inputs of the first and third multipliers, the sine output of the difference frequency generator is connected to the inputs of the second and fourth multipliers, the outputs of the second and the third multiplier connected to the inputs of the sine adder, the output of the first multiplier directly, and the output of the fourth multiplier through a sign inverter connected to the inputs of the cosine adder, the outputs of the sine and cosine adders serve as the corresponding outputs of the mixer.