SU1361575A1 - Device for computing walsh-hadamar transform coefficients - Google Patents

Abstract

The invention relates to computing and can be used in digital signal processing. The aim of the invention is to simplify the device. The device contains information inputs 1, adder 2 correction, converters 3 codes, inputs 4 and outputs 5 converters code, inputs to correction codes, switches 7, trigger 8, resetter, setting inputs 9 and 10 of the mode trigger, outputs 11 and 12 of the device, group 13 elements OR. The goal is achieved by introducing a correction to the first input signal sample. 2 ill., 1 tab. . About And III I And (L with Oi JV ate tLjl

Description

The invention relates to radio engineering, in particular to spectral analysis, and can be used in digital signal processing.

The aim of the invention is to simplify the device.

Fig. 1 shows a functional diagram of a device for calculating Walsh-Hadamard conversion factors; Fig. 2 is a diagram-a of a multi-code-to-two-converter converter.

The device (.1) contains paraphase information inputs with buses 1 and 1, respectively, direct and reverse codes, adder 2 corrections, converters 3 multi-code to two-row with input buses 4 multi-code and output buses 5 to two-code, 6 direct and 6 additional device correction codes, switches 7, trigger 8 modes with buses 9 and 10, setting the trigger in one and zero states, information output 11 of the device, output 12 modified result of the device, a group of elements OR 13 and adders 14.

Each multi-code-to-two converter (Fig; 2) contains groups of adders 15 consisting of subgroups of adders 16 that combine 1-input single-digit adders 17 of the same weight.

Each switch 7 (fig.O contains two groups of elements And 18.

The device works as follows.

Paraphase information inputs of the device from the direct and inverse outputs (bus 1, 1) of the memory registers (not shown) simultaneously receive 2 samples of the signal. According to the values of the Walsh-Hadamard function W; (X) Each of the signal samples in the forward and reverse code is fed to a group of buses 4 of the multi-axis code of each of the converters 3 codes.

The correction code is needed to eliminate the computation error arising from the replacement of the subtraction of the pairs of numbers by the addition operation in which the subtracted is represented in the reverse binary code. To convert a negative number from the return code to an additional sufficient

recci in the form of adding one to the lower order bit of the reverse code. When converting the Walsh-Hadamard input signal, the zero coefficient is obtained by summing all the samples of the input signal. The remaining coefficients are obtained by summing and subtracting the D1auh sample groups of the input signal on each N / 2 sample.

In the known device, a correction code equal to the constant N / 2 is added to all output coefficients, except the zero one. To reduce the number of adders required for this in the proposed device, a correction code equal to the constant N / 2 is added to the zero count of the input signal, which is equivalent to adding the correction code equal to N / 2 to each of the output conversion coefficients.

In order to compensate for the extra correction of the zero coefficient in the proposed device, an additional correction of the zero coefficient is made at the input of the first converter 3 of the multi-channel code to the two-channel one by adding the correction number equal to the additional code to the number N / 2.

Consider the operation of the device, for example.

Let the Walsh-Hadamard transformation matrix be given for

1111

1 1-1-1

1-1 1-1

1-1-1 1

and the signal is converted (see table):

It is obvious that Y A X is equal; YO .- 2; Y1 + 2; Y2 4; Y3

 four.

3

. At the inputs of converters 3 of multi-code in the known device we will have (correction code 0010 is underlined, the number X is the inversion of the number X, the calculations are carried out using modules 2)

HgX, 0010 +

12; + Hg + X, + 0010 0000 + 0000 + 0010

,

X.

0010 + 0001 0010 0100 Х „+ X. + 0001 4.

+ X +

+ 1111

 ;

+ Xj 0000

X, + 0010 + 0000 +.

X,

nil

+0010 + 0010

YS 0010

0100 in the proposed device on the inputs of the converters 3 we have

Ho (XO + 0010) mod 2 0100;

YO (XO + XI + X2 + XS + 1110) mod 2 0100 +1110 + 1111 +

ilil + 1110 1110 2; , Yl (XO + XI + X2 + HZ) mod 2 0100 + 1110 + 0000 + 0000 + 0010

25 - Y2 (XO + XI + X2 + X3) mod

0100 + 0001 + 1111 + 0000 0100

four;

Y3 (CW

2

0100 4.

+ XI + XI + 0001 + 0000 +

+ KhZ) mod 2 1111 0100

Claims (1)

Invention Formula A device for calculating Walsh-Adamar transformation coefficients, containing a group of OR elements, 2 switches, 2 adders, a mode trigger, a group of converters of a multi-channel code to dvgr dn, each of which contains K groups of M sub-groups the same weight j, where j - razr - moreover, information outputs sum- jth Yes, mators of the jth subgroup (, M, where M is the size of the input samples). 1361575 ten 15 20 25 thirty 35 40 45 The i-th (1 1, K-1) groups are respectively connected to the inputs of the adders of the j-th and subgroup of the (1 + 1) -th group, the transfer outputs of the adders of the j-th subgroup of the i-group and respectively are connected to the inputs of the adders w-y ( t j + l, + 1) subgroups of the (1 + 1) -th group, the B-th information input of the device is connected to the inputs of the adders of the first group of converters of the multidirectional code into the dual-mode (В 2, 2), information outputs of the adders K- and groups of the C-th converter of the multi code in c. dvuhrydny respectively connected to the information inputs of the C-th switch (C 1, 2), the first output of which is connected to the input of the C-th adder, the output of which is connected to the first input of the C-th element OR group, the output of which is connected to the output of the modified the result of the device, the direct and inverse outputs of the mode trigger are connected respectively to the first and second control inputs of the switch (C 1, 2), the output of which is connected to the second input of the Cth element of the OR group and to the information output of the device; in I and settings in О, the mode trigger is connected to the first and second installed inputs of the device, respectively, for which, for the sake of simplicity, it contains a correction adder, the first input of which is connected the first information input of the device, the second input of the correction adder is connected to the input of the additional correction code of the device, the input of the first converter of the multi-channel code to the dual-mode one is connected to the input of the direct correction code of the device, the output of the correction adder is connected to the inputs of the adders The first group of the C-th multi-code converter into a two-band one. / 7 J /five (five sixteen 15 li LR Editor V. Bugrenkova Compiled by M.Silin Tehred A. Kravchuk Corrector. L. Patay Order 6292/49 Circulation 671 Subscription VNRSHPI State Committee of the USSR for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 fui2