RU2278475C1 - System for transferring discontinuous information - Google Patents

Abstract

FIELD: electric communications engineering, in particular, engineering of multichannel communication systems.

SUBSTANCE: system for transmitting discontinuous information contains at transmitting side information sources, multipliers, adder, clock generator, Walsh functions generator, 2ⁿ keys (where 2ⁿ - number of outputs of Walsh functions generator) and frequency splitter, two elements of one-sided conductivity and 2ⁿ additional multipliers, and on receiving side - clock generator, Walsh functions generator, multipliers, integrators, information receivers, 2ⁿ keys and frequency splitter, two elements of one-sided conductivity and 2ⁿ additional multipliers. As a new addition, on transmitting side two one-sided conductivity elements are inserted and 2ⁿ additional multipliers, and on receiving side - two one-sided conductivity elements and 2ⁿ additional multipliers.

EFFECT: decreased frequency band due to decreased effective width of channel carriers spectrum.

6 dwg, 1 tbl

Description

The invention relates to the field of telecommunications, in particular to multi-channel communication systems.

A device for transmitting and receiving discrete information is known, containing on the transmitting side information sources, multiplication units, a Walsh function generator, an adder, and on the receiving side, information receivers, a Walsh function generator and correlators consisting of multiplication units and integrators (see German patent No. 1959175, class H 04 J 11/00, 1976).

However, in this device for transmitting and receiving discrete information as channel carriers Walsh functions are used, the system of which has a large effective spectrum width, which leads to low efficiency of using the frequency band allocated for this device.

The closest in technical essence to the present invention is a discrete information transmission system containing on the transmitting side information sources, multipliers, an adder, a clock, a Walsh function generator, 2 ⁿ keys (where 2 ⁿ is the number of outputs of the Walsh function generator) and a frequency divider, and the outputs of the information sources are connected to the first inputs of the multipliers, the outputs of which are connected to the inputs of the adder, the output of which is connected to the communication line, the output of the clock generator is connected to the input of the generator fu Walsh functions and to the input of the frequency divider, the output of the frequency divider is connected to the control inputs of the keys, the first information input of each i-th (i = 1, ..., 2 ⁿ ) key is connected to the i-th output of the Walsh function generator, the second information input each i-th key is connected to the (2 ⁿ -1-i) -th output of the Walsh function generator, the output of each key is connected to the second input of the corresponding multiplier, and on the receiving side there is a clock generator, multipliers, integrators, information receivers, 2 ⁿ keys and a frequency divider, the output of the clock generator being connected with the input of the Walsh function generator, the first inputs of the multipliers are connected to the communication line, the outputs of the multipliers are connected to the inputs of the integrators, the outputs of which are connected to the inputs of the information receivers, the output of the clock generator is connected to the input of the frequency divider, the output of which is connected to the control inputs of the keys, the first information input of each the key is connected to the i-th output of the Walsh function generator, the second information input of each key is connected to the (2 ⁿ + 1-i) -th output of the Walsh function generator, and the output of each key is connected to the second at the input of the corresponding multiplier (see RF patent No. 2025901 according to the application No. 4844150/09 (069146) from 06.25.90, cl. H 04 J 11/00).

However, in this discrete information transmission system, signals are used as channel carriers, the system of which has a large effective spectral width, which leads to low bandwidth efficiency.

The aim of the invention is to reduce the frequency band by reducing the effective spectrum width of the channel carriers.

This goal is achieved by the fact that in the known system for transmitting discrete information containing information sources, multipliers, an adder, a clock generator, a Walsh function generator, 2 ⁿ keys (where 2 ⁿ is the number of outputs of the Walsh function generator) and a frequency divider, and the outputs of the information sources are connected to the first inputs of the multipliers, the outputs of which are connected to the inputs of the adder, the output of which is connected to the communication line, the output of the clock generator is connected to the input of the Walsh function generator and to the input of the divider i frequency, the output of the frequency divider is connected to the control inputs of the keys, the first information input of each i-th (where i = 1, ..., 2 ⁿ ) key is connected to the i-th output of the Walsh function generator, the second information input of each i-th the key is connected to the (2 ⁿ -1-i) -th output of the Walsh function generator, and on the receiving side, a clock generator, a Walsh function generator, multipliers, integrators, information receivers, 2 ⁿ keys and a frequency divider, and the output of the clock generator is connected to input of the Walsh function generator, the first inputs of the multipliers are connected to communications, the outputs of the multipliers are connected to the inputs of integrators, the outputs of which are connected to the inputs of the information receivers, the output of the clock generator is connected to the input of the frequency divider, the output of which is connected to the control inputs of the keys, the first information input of each key is connected to the i-th output of the Walsh function generator, the second information input of each key is connected to the (2 ⁿ + 1-i) -th output of the Walsh function generator; two elements of one-sided conductivity and 2 ⁿ additional multipliers are introduced on the transmitting side, and the output each key is connected to the first input of the corresponding additional multiplier, the output of which is connected to the second input of the corresponding multiplier, the 2 ^n- th output of the Walsh function generator is connected to the inputs of the one-sided conductivity elements, the output of the first one-sided conductivity element is connected to the second inputs of kx additional multipliers (where k = 1, ..., 2 ^n-1 ), the output of the second one-way conduction element is connected to the second inputs lx of additional multipliers (where I = 2 ^n-1 +1, ..., 2 ⁿ ), and on the receiving side there are two elements one rn conductivity and 2 ⁿ additional multipliers, the output of each key being connected to the first input of the corresponding additional multiplier, the output of which is connected to the second input of the corresponding multiplier, the 2 ^n- th output of the Walsh function generator is connected to the inputs of the one-sided conductivity elements, the output of the first one-sided conductivity element is connected with the second inputs of kx additional multipliers (where k = 1, ..., 2 ^n-1 ), the output of the second one-way conduction element is connected to the second inputs of lx additional multiplies oil (where I = 2 ^n-1 +1, ..., 2 ⁿ ).

Figure 1 presents a structural electrical diagram of the proposed system for transmitting discrete information, figure 2 is a structural diagram of a two-input key, figure 3 is a timing diagram illustrating the process of forming the carrier of channel information S '(6, θ) in the proposed transmission system, figure 4 is a view of channel carriers formed in the analogue, figure 5 is a view of channel carriers formed in the prototype, figure 6 is a view of channel carriers formed in the proposed transmission system.

The discrete information transmission system contains, on the transmitting side, an information source 1, multipliers 2, an adder 3, a clock generator 4, a Walsh function generator 5, keys 6, a frequency divider 7, multipliers 8, a clock generator 9, a Walsh function generator 10 on the receiving side, integrators 11, information receivers 12, keys 13, frequency divider 14. The system also contains on the transmitting side elements 15 and 16 of one-sided conductivity, additional multipliers 17, and on the receiving side - elements 18 and 19 of one-sided conductivity, additional multipliers 20. The keys contain an inverter 21, multipliers 22 and 23, the adder 24.

The system for transmitting discrete information works as follows. Discrete information in the form of “0” or “1” may appear at the outputs of information sources. The duration of zero or one is equal to the duration of the channel carrier supplied to the control input of the multiplier 2, the information input of which is connected to the output of the corresponding source I of information.

The clock generator 4 generates pulses whose duration is equal to half the period of its frequency arriving at the clock input of the generator 5 of Walsh functions, at the outputs of which 2 ⁿ Walsh functions are formed. The pulses from the output of the clock generator 4 are also supplied to the input of the frequency divider 7, having a division ratio of 2 ^n-1 . Thus, during the first half-period of the formation of Walsh functions at the output of the frequency divider 7, “0”, arriving at the control inputs of the keys 6. During the second half-period of the formation of Walsh functions at the output of the frequency divider 7, “1” is formed, coming at the control inputs of the keys 6.

Upon receipt of the key 6 "0" at the control input, a signal is generated at its output that is transmitted to its first information input, and when a key 6 "1" is received at the control input of the key, a signal is generated at its output that comes to its second information input.

Consider in more detail the functioning of the keys 6 (see figure 2).

When entering the control input z of the key 6 "0", the input of the element is NOT 21 and the first input of the second multiplier 23 receives "0". As a result, the signal supplied to the first information input x _{1 of the} key 6, through the multiplier 22 and the adder 24 is output y. The signal supplied to the second information input x ₂ does not go to the output y, since the first input of the multiplier 23 receives "0" from the control input z.

When entering the control input z of the key 6 "1", the input of the element is NOT 21 and the first input of the multiplier 23 receives "1". As a result, the signal supplied to the second information input x _{2 of the} key 6, through the multiplier 23 and the adder 24, is output at the key 6. The signal fed to the first information input x _{2 of the} key 6 does not go to the output, since the first input the multiplier 22 receives "0" from the output of the element NOT 21.

Thus, the signal S (i, θ) at the output of each key 6 has the form of two “stitched” half-periods of the corresponding Walsh functions. The signals from the outputs of the keys 6 are fed to the first inputs of the corresponding additional multipliers 17. The second inputs of the multipliers 17, having serial numbers from the 1st to the 2nd ^n-1st, receive positive pulses from the output of the one-way conduction element, passing only pulses having the polarity " + ”, From the 2nd ^n- th output of the generator of 5 Walsh functions. The second inputs of additional multipliers 17, having serial numbers from (2 ^n-1 +1) th to 2 ⁿ th, receive negative pulses from the output of a one-sided conduction element, passing only pulses having a polarity of “-”, from 2 ^n- th output generator 5 Walsh functions. As a result, at the outputs of the additional multipliers 17, 2 ⁿ carriers of channel information are formed, the duration of each of which is equal to the duration T of the Walsh functions, and the pulse duration Δt of the generated carriers is equal to the pulse duration Δt of the carriers generated by the prototype at the same clock frequency 4.

The orthogonality of all 2 ⁿ formed transporters can be verified by multiplying any of them and integrating the multiplication result over time T.

The second inputs of the multipliers 2 thus receive the channel information carriers, which are multiplied by “1” or “0” in them, depending on what goes to the first input of the corresponding multiplier 2, after which the multiplication results through the adder 3 enter the communication line.

At the receiving side, the group signal is fed to the information inputs of the multipliers 8, and the second inputs of the multipliers 8 at this time receive reference signals from the outputs of the corresponding additional multipliers 20, which are formed in the same way as the carriers of channel information on the transmitting side. In multipliers 8, the group signal is multiplied by the corresponding reference signals, and the results for the duration of the channel information carriers are integrated in the respective integrators 11. At the outputs of the integrators 11, the received discrete information is generated, which is received at the inputs of the information receivers 12.

Figure 3 shows the timing diagrams illustrating the process of forming the channel carrier S '(6, θ) in the eight-channel discrete information transmission system in the case of receipt of "1" from the output of source 1 to the information input of the corresponding multiplier 2. The diagrams show the temporary state:

a) the output of the clock generator 4;

b) the seventh output of the generator 5 of Walsh functions, on which the function Wal (6, θ) is generated, which arrives at the first information input of the seventh key 6;

c) the second output of the generator 5 of Walsh functions, on which the function Wal (1, θ) is generated, which arrives at the second information input of the seventh key 6;

d) the output of the frequency divider 7;

d) the output of the seventh key 6, on which the signal S (6, θ) is generated;

f) 2 ^n- th output of the generator 5 of Walsh functions, on which the function Wal (7, θ) is generated, which is supplied to the inputs of the elements 15 and 16 of one-sided conductivity;

g) the output of the element 16 of one-sided conductivity, passing negative pulses;

h) the output of the seventh additional multiplier 17, on which the signal S '(6, θ) is generated;

i) the output of the seventh source 1 information;

j) the output of the seventh multiplication block 2, on which the channel carrier S 'is formed (6, θ).

It is known that for the transmission of channel carriers formed in the transmission system, it is necessary to provide a frequency band for transmission of the widest channel channel carrier (see Varakin L.E. Theory of signal systems. - M.: Soviet radio, 1978, p.11). The more blocks a signal has, the greater the effective signal spectrum width Wμ _eff. (see Varakin L.E. Theory of signal systems M .: Soviet Radio, 1978, p.208). In this case, a block sequence of elements having a phase of 0 or π, that is, a sequence of positive or negative signal elements (see Varakin L.E. Theory of signal systems. - M .: Soviet radio, 1978, p.177, first line).

In the analogue (see the German Federal Patent No. 1959175, class H 04 J 11/00, 1976), channel carriers are used, described by Walsh functions and having the number of blocks μ = 1,2,3, ..., N, where N is the number elements of Walsh functions (see figure 4).

Therefore, the channel carriers formed by the analog have different effective spectral widths, and the channel carrier has the largest effective width, in which the number of blocks is μ = 2 ⁿ = N (i.e., meander):

where Δt is the duration of the signal element (see L. Varakin, Theory of signal systems. - M.: Soviet radio, 1978, p.208, table 11, 1, second line).

In the prototype (see RF patent No. 2025901 for application No. 4844150/09 (069146) dated 06/25/90, class H 04 J 11/00), channel information carriers are used, which are signals having the number of blocks (see Fig. 5 ):

, определяется по формулеThe effective spectrum width of the most broadband carrier used in the prototype, taking into account

determined by the formula

(see Varakin L.E. Theory of signal systems. - M.: Soviet Radio, 1978, p. 208, relation (11.11)).

In the proposed system for transmitting discrete information, all carriers have the same number of blocks (see Fig.6):

.and the value of the largest effective width of the carrier spectrum is determined from relation (3) taking into account

.

The table presents the results of calculations of the effective spectral width Wμ _{eff of the} most broadband carriers used by the analogue, prototype and the proposed discrete information transmission system for a different number of channels.

Table Channel carriers Effective spectrum width Wμ _eff for the number of channels, k four 8 16 32 64 Formed by analog 10,583 21,909 44.54 89.8 180.31 Molded by prototype 8.94 16.97 32,99 64,99 128,99 Formed by the proposed transmission system 7,483 15,491 31,496 63,498 127,499

According to the results of the table, we can conclude that the gain in the frequency band necessary for the proposed transmission system, in comparison with the analogue, is 29.29% for any number of channels k. Compared to the prototype, the gain is 16.33% for k = 4; 8.71% for k = 8; 4.51% - for k = 16, etc.

The use of the invention can significantly reduce the frequency band necessary to ensure the operation of the system for transmitting discrete information.

Claims (1)

A discrete information transmission system containing on the transmitting side information sources, multipliers, an adder, a clock generator, a Walsh function generator, 2 ⁿ keys (where 2 ⁿ is the number of outputs of a Walsh function generator) and a frequency divider, the outputs of information sources being connected to the first inputs of the multipliers the outputs of which are connected to the inputs of the adder, the output of which is connected to the communication line, the output of the clock generator is connected to the input of the Walsh function generator and to the input of the frequency divider, the output of the frequency divider is connected to the control using the key inputs, the first information input of each i-th key (where i = 1, ..., 2 ⁿ ) is connected to the i-th output of the Walsh function generator, the second information input of each i-th key is connected to (2 ⁿ -1 -i) to the output of the Walsh function generator, and on the receiving side, a clock generator, Walsh function generator, multipliers, integrators, information receivers, 2 ⁿ keys and a frequency divider, the output of the clock generator being connected to the input of the Walsh function generator, the first inputs of the multipliers connected to the communication line, the outputs of the multipliers are connected to the inputs and integrators whose outputs are connected to the inputs of the information receivers, the output of the clock generator is connected to the input of the frequency divider, the output of which is connected to the control inputs of the keys, the first information input of each key is connected to the i-th output of the Walsh function generator, the second information input of each key is connected to ( 2 ⁿ + 1-i) -th Walsh function generator output, characterized in that, in order to reduce bandwidth by reducing the effective width of the spectrum of channel vectors, introduced into it in the transmitting side two e ementa unidirectional conductivity and ⁿ 2 additional multipliers, the output of each switch is connected to a first input of a respective further multiplier, whose output is connected to a second input of the respective multiplier 2 ⁿ -th Walsh function generator output is connected to inputs of one-way conduction element, an output of first one-way conduction coupled to second inputs of the multipliers additional kx (where k = 1, ..., 2 ^n-1), the output of the second element is connected to the unidirectional conductivity second inputs complementary l-x -negative multipliers (where l = 2 ^n-1 +1, ..., 2 ^n), and at the receiving side - two-sided conduction element 2 and additional ⁿ multipliers, wherein each switch output is connected to a first input of a respective further multiplier, whose output connected to the second input of the corresponding multiplier, 2 ^n- th output of the Walsh function generator is connected to the inputs of the one-sided conductivity elements, the output of the first one-sided conduction element is connected to the second inputs of kx additional multipliers (where k = 1, ..., 2 ^n-1 ), second element output one-sided conductivity is connected to the second inputs of l-x additional multipliers (where l = 2 ^n-1 +1, ..., 2 ⁿ ).

Images