The multi-way transmission of digital signals
(57) Abstract:Usage: in telecommunication, communication systems, code compaction and separation channels (signals). The essence of the invention: enhancing protection of sealed channels from mutual interference is achieved by the fact that the losing party in each of the N channels channel signal formed by amplitude, which is the difference of the amplitude of the transmitted useful information signal and the amplitude of the interference in the channel seal, then the received channel signals condense. 1 Il. The invention relates to telecommunication and can be used in communication systems with parallel transmission of information, also for sealing wire, radio relay and satellite communication lines.Goal is to improve security of sealed channels from mutual interference.The drawing shows a block diagram of the device forming group signal, illustrating the proposed method.The device contains an element of subtracting 1, multiplier 2, the generator 3 channel filters, an adder 4, block 5 calculate the correction voltage, the memory element 6.Working diagram of the device forming group signal is of duration T with amplitude1WITH2. . . WITHN. In the j-th unit 5 calculates the voltage correction amplitude information signals, second input unit 5 continuously signals in the form of a constant voltage amplitude equal to the value of the corresponding correlation coefficients Vi1Vi2. . . ViN, i j. The received pulse correction voltage Cjis subtracted from the corresponding information of the pulse amplitude Cj. All operations are performed without delay, so the adjusted pulse amplitudes C, i= , proceed to the appropriate multiplier products 2, where they are multiplied with the channel signals Si(t) are summed in the adder 4, and issued in the transmitter.Evaluate the effectiveness of the claimed method of signal transmission. When you change the amplitude information signals simultaneously in all channels in accordance with the calculated values of U, i= get a group signal
Xg(t) = CiSi(t), where
Ci= Ci+ CiCi= CiVij,
and the voltage of the report at the output of the j-th corrector
U= Ci+ Ci)Vij+ V =
Compare the capacity of interference before and after the correction of the amplitude information SIM> = = (N-1)V2,
and after correction
PRR= D CiV (N-1)V2(N-1)V2(N-1)2V4< / BR>Hence, the average gain of the mode of transmission of signals is equal to RRR/PRR= 1/(N-1) V2,
and it will take place at the V < 1/. The MULTI-WAY TRANSMISSION of DIGITAL SIGNALS, where N is formed reference quasiorthogonal signals, such signals of all channels is folded, the aggregate signal is transferred into a high-frequency region, amplify and transmit over the communication channel, wherein the sealing signal of each channel is formed by multiplying the corresponding j-th reference quasiorthogonal signal to a rectangular pulse with amplitude Cjiwhere j = and Cjidetermined by the formula
Cij= Cj- Cirij,
where rijthe correlation coefficient of the i and the j-th reference quasiorthogonal signals;
Cij = value of the amplitudes of the transmitted digital information signals.
FIELD: communications engineering.
SUBSTANCE: proposed band selection method for mobile orthogonal frequency division multiple access communication system includes following steps to classify procedures of band selection between sending end and receiving ends with respect to original band selection process, passband width selection process, and periodic band selection process: determination of source band selection code (SC)number for source band selection process; SC number to request passband width for passband width request selection process and periodic SC number for periodic band selection process; determination of periodic SC deferment value in compliance with periodic SC number, and transmission of source SCs, passband width request SC, periodic SCs, and periodic SC deferment values on receiving ends.
EFFECT: minimized time for band selection access.
22 cl, 3 dwg, 4 tbl
FIELD: communications engineering.
SUBSTANCE: stationary wireless access system has, as a rule, user's room equipment unit connected through Ethernet interface to personal computer or to local network and base station unit connected through Ethernet interface to network. User's room equipment unit as such is easily installed by user while base station unit is usually mounted on mast at distance of 1 to 5 miles (1/6 to 8 km) from user's room equipment unit. Both the latter and base station unit usually incorporate integrated transceiver/data switch that provides for radio-frequency communications in the range of 2.5 to 2.686 GHz. Multiplexing with orthogonal frequency division of signals is used during transmission between user's room equipment units and base station ones over ascending and descending lines.
EFFECT: provision for using outwardly accessible antenna affording transmission within line-of-sight range.
70 cl, 19 dwg
FIELD: electrical and radio communications; underwater, radio, radio-relaying, and meteorological communication lines.
SUBSTANCE: start-stop communication system that has on sending end signal shaping and transfer unit 1 and on receiving end, receiver 2, amplitude detector 3, low-pass filter 4, first comparator 6, memory device 7, shift register 8, first decoder 9, switch 10, synchronizing unit 11, pulse shaper 12, pulse burst shaper 13, binary counters 14, 17, signal retrieval and storage device 19, and threshold device 5 is provided in addition with newly introduced second comparator 15, RS flip-flop 16, and second decoder 18.
EFFECT: reduced malfunction probability of proposed communication system.
1 cl, 3 dwg
FIELD: mobile telecommunication systems.
SUBSTANCE: device for decreasing relation of pike power to average power signal, sent along N(=2r) sub-bearing lines in transmitting device, having encoders for block encoding of w input data, where r - real number > 2, and output of N code symbols, has: serial-parallel converter for transforming data flow to w-(r-2) parallel data flows, where w - length of information word, first coder for receipt of w/2 parallel data flows from w-(r-2) parallel data flows from serial/parallel converter, block encoding of w/2 parallel data flows and output of N/2 first code symbols, generator of input operators for generation of r-2 data flows of input operators, in accordance to w-(r-2) parallel data flows, and second coder for receiving parallel data flows from serial/parallel converter, which were not received at first coder and (r-2) data flows from input operators, block encoding of received data flows and output of N/2 second code symbols, while r-2 data flows of input operators provide for complementarity of N code symbols.
EFFECT: higher efficiency, higher reliability.
6 cl, 22 dwg
FIELD: engineering of devices and methods for receipt and synchronization in direct digital satellite broadcast system.
SUBSTANCE: satellite system uses modulation with temporal signals separation and single-frequency network of ground-based re-emitting stations, each of which introduces a delay to ground signal. Delay allows to provide for coincidence of time of receipt of early modulated signal in the center of ground broadcasting zone with time of receipt of appropriate late modulated signal, thus improving switching between ground and satellite signals in receiver. Delay also compensates processing delay, occurring during conversion of satellite modulated stream under direct visibility conditions to multi-frequency modulated stream for transmission of satellite modulated stream under direct visibility conditions to user receivers. Delay is also adjusted in accordance to distance difference between each ground-based re-emitting station and satellite and between each station and center of ground-based broadcasting zone. Adjustment as described above optimizes receipt of temporal signals separation modulated and multi-frequency modulated signals by means of synchronization in the center of single-frequency system of phase of multi-frequency modulated signals, re-emitted from re-emitting stations of single-frequency system.
EFFECT: increased quality of radio-signal receipt.
8 cl, 12 dwg
FIELD: engineering of devices for generating series of preamble with low ratio of pike to average power in communications system with orthogonal multiplexing and frequency separation of channels.
SUBSTANCE: in accordance to method, first series of preamble is generated, wherein odd data of input series of preamble are transformed to zero data, and even data of aforementioned series are transformed to nonzero data, first series of preamble is transmitted through one of two antennas, second preamble series is generated, wherein even data of input series of preamble are transformed to zero data, and odd data of aforementioned series are transformed to nonzero data, second series of preamble is transmitted through another antenna.
EFFECT: increased efficiency.
6 cl, 10 dwg
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
FIELD: engineering of communication systems, using multi-access layout based on orthogonal multiplexing circuit with frequency division.
SUBSTANCE: communication system divides whole range of frequencies onto a set of sub-frequency ranges. Receiver of information about quality of channels receives information about quality of channels for each one of a set of frame cells, occupied during first time span by a set of frequency-time cells, occupied by second time span and a given number of sub-frequency ranges, transferred via check communication channel from receiver. Module for sorting frame cells analyzes information about quality of check communication channels and sorts frame cells in accordance to information about quality of channels. Module for assigning sub-channels, if transfer data exist, transfers data through a frame cell with best channel quality among other frame cells.
EFFECT: increased data transfer speed.
5 cl, 6 dwg
FIELD: electric radio engineering, possible use for increasing quality of electric communication, especially in multi-frequency wireless communication systems.
SUBSTANCE: method for decreasing ratio of peak signal power to its average ratio PAPR in multi-frequency communication systems, in which information symbol is formed by a set of signals, each one of which is centered on one of multiple bearing frequencies, is characterized by the fact that in transmitter a set of bearing frequencies is divided on several sections - subsets of bearing frequencies, information symbol, PAPR value of which does not exceed required threshold PAPR0, is transferred via all carriers, information symbol, value PAPR of which exceeds required threshold PAPR0 is divided on several sub-symbol sections, while number of these sections equals number of sub-carrier subsets, each section of symbol is transferred same as full symbol, wherein data are only transferred on one group of carriers, while other carriers are not modulated, in receiver, arrival of incomplete symbol is identified by analysis of amplitudes of carrier signals, which are not modulated in case of symbol division. Multi-frequency communication system is characterized by construction of receiver and transmitter, adapted for execution of operations, included in proposed method.
EFFECT: preservation of high channel capacity with simplified correction procedure.
2 cl, 12 dwg
FIELD: the invention refers to the field of radio technique and may be used for transmission of information with the aid of signals with orthogonal frequency multiplexing.
SUBSTANCE: the technical result is in increasing accuracy of synchronization of signals with orthogonal frequency multiplexing and that in its turn provides reduction of error possibility at reception of these signals even in such complex propagation conditions as shot-wave range channels. For this in the receiving set of the known equipment two memory blocks, two commutators, a maximum choice selection block, a meter and a time intervals calculation block are introduced.
EFFECT: increases accuracy of signals.