The radio connection broadband system of the increased speed in the process of transmitting the information
Bauman Moscow State Technical University, MSTU, 5, bldg. 1, 2-nd Baumanskaya str., Moscow, 105005, Russia
It has been worked out the approach for the synthesis radio system with high demands to the process of high demands to the process of transmitting the information. This approach is based on the analysis and the application of the more energy efficient designs of a signal. That means using of multi-line constructions of the radio system with the orthogonal code devision of channels into 2 types: non-linear code sequences and multilevel quadrature amplitude-inverse modulation of the signals.
Each channel consists of 2 quadrature channels. The code sequence P1 is used in the inphase channel for transmitting m-symbols of binary information. And the code sequence P2 is used in the quadrature channel for transmitting the second combination of m-symbols of binary information.
Moreover, P1 is orthogond to P2. The high-order digit of m-digit code combination specifies the kind of the sequences P1 and P2. The rest of the m-1 information categories define a discrete value of the amplitude sequence.
In its turn, in each quadrature channel of the receiver there is a convolution of the sequences P1 and P2. Then the sign of the response signal detected is being determined in the demodulator. Then there is a determination of the number of the amplitude interval in each quadrature channel (m-1). This number will correspond to the information category in which the response amplitude of a received signal is. That means, there is a simultaneous assessment of 2m binary units of accepted information in each channel of a receiver.
To determine the values of noise resistance characteristics that’s enough to estimate it in one of the quadrature channel. The lower boundary interval’s value and their absolute value must ensure the selection of the amplitude signals with specified probability of false admission. The size of the intervals has different value, as the resulting probability of the symbol’s false admission depends on reliability of determining the sign and chosen interval amplitude signal’s number.
Dispite the fact that the sequence provides the necessary Walsh correlation characteristics of the ensemble it is extremely limited, which is of significant disadvantage.
It is proposed to the developed modulation type, which was named m-QAIM — multiposition quadrature amplitude-inverse modulation, using code division radio using sequences based on nonlinear full code ring (NFCR).
The article also shows a diagram of a radio transmission device that was developed based on the algorithm proposed SCC using wideband signal.
Thus, the practical realization of the experiment allowed the opportunity to show the efficiency of frequency and power resources in the radio channel.
Keywords:signal-code construction, amplitude-modulation inverse, spectral and energy efficiency, noise immunity, secretiveness, pseudorandom sequence, the orthogonal signals
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