Letunov
Leonid Letunov, Gomel BY
Patent application number | Description | Published |
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20090232253 | Method and system for creating quadrature modulation signal constellations with arbitrary spectral efficiency - Methods, systems, transmitters, and receivers implement and use Quadrature Amplitude Modulation QAM2N modulation types and constellations, where N is a real number, e.g., 1.5; 1.33; 2.5; 3.5. The methods, systems, transmitters, and receivers use constellations with the number of points on the circle not equal to a power of two, sending QAM signals of zero power together with other QAM signals, and/or sending sequences of QAM signals of different types. | 09-17-2009 |
20100195701 | Method of packet transmission and reception of Quadrature Amplitude Modulated signals in a frequency hopping radio system - A method to decrease the amount of time required to achieve carrier and clock frequency synchronization in QAD packet communications systems including frequency-hopping radio systems using pseudo-noise data sequences to mark the beginning of data transmissions and carrier frequency switches. | 08-05-2010 |
Leonid A. Letunov, Gomel BY
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20100177835 | Method For Transmitting And Receiving Quadrature Amplitude Modulation Signals, A System For Carrying Out Said Method, A Machine-Readable Carrier And The Use Of A Method For Synchronously Receiving Quadrature Amplitude Modulation Signals - The invention relates to signal transmission. The use of the invention for transmitting and receiving quadrature amplitude modulation signals on unlicensed frequency bands makes it possible to lower a demodulation threshold owing to a low synchronisation threshold. The inventive method consists in extending a burst of M m-level quadrature amplitude modulation signals with the aid of two pseudo-random sequences, one of which is periodically inverted in some bursts, thereby making it possible to extract, on a receiving side, the quadrature amplitude modulation signal components corresponding to a meander signal of the pseudo-random sequence inversion (the frequency of which is known). The inventive method is carried out by means of a corresponding system in a hardware and software mode. Moreover, said method can be used for synchronising the reception of quadrature amplitude modulation signals. | 07-15-2010 |
Leonid Alexeevich Letunov, Gomel BY
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20090022248 | Method for Demodulating the Signal of Multiple-Position Frequency Manipulation with Equidistant Frequency Spreading, Demodulator for this Signal, and Computer-Readable Medium - This invention relates to signal transmitting engineering. The use of the inventive method demodulation of a signal of multiple position frequency manipulation with equidistant frequency spreading allows to reduce the threshold of demodulation and to ensure a quality of demodulation, which is at least identical to that of a quasi-optimal demodulator. To obtain such a result, a frequency grid is formed with a possibility of precise tuning of frequency spreading; during the reception, values having a maximum module of reception signal are extracted at all frequencies switchable values at clock frequency, this clock frequency is extracted from maximum of the received signals and is used for a precise tuning of the frequency spreading; a grid of tunable frequency is tuned with a precisely tuned frequency spreading for exact values of a frequency of received signal, and demodulation is effected by the way of coherent reception of the received signal, using only one from quadrature signals to decide whether a signal of a determined frequency is absent or present among the mentioned exact values of frequency. | 01-22-2009 |
20090122912 | Method for Transmitting and Receiving Quadrature-Amplitude Modulation Signals, System for Implementing Thereof, Machine-Readable Medium, and Application of the Method for Synchronizing Reception of Amplitude Modulation Signals - The invention relates to signal transmitting engineering. The use of the inventive method in systems for transmitting and receiving quadrature amplitude-modulation signals (QAM) exhibiting a low carrier frequency synchronisation threshold makes it possible to decrease a demodulation threshold by means of said low carrier frequency synchronisation threshold. The result is attainable by supplementing a burst of M m-level sensitive QAM symbols by predetermined symbols, one part of which remains constant form one burst to another and the other part is periodically invertible in certain bursts, thereby the QAM signal components corresponding to the additional predetermined symbols (whose frequencies are known) are extracted on a receiving side. The inversion frequency is determined according to said components, thereby making it possible to eliminate the ambiguity of the receiving frequency synchronisation control and to approach the Shannon's threshold. | 05-14-2009 |