Method for the transmission of digital data
First Claim
1. Method for demodulating received data modulated in a received data signal, said signal being composed of several transmission sections of fixed length, each transmission section having a fixed carrier frequency, which is changing in steps from one transmission section to the next and is modulated by means of m discrete permitted phase values by phase modulation of a carrier frequency, each transmission section containing the data in the form of a plurality of symbols and said signal containing the data to be transmitted plural times, including using different transmission sections for the same data, said method comprising the steps of:
- determining for each transmission section a mean phase value (φ
i);
determining the phase difference (Δ
φ
ik) between the symbol phase (φ
ik) and the mean phase value (φ
i) of the associated transmission section for each symbol within a transmission section;
allocating a weighting factor (Wik, Wi'"'"'k'"'"') which functionally depends on the phase difference (Δ
φ
ik) multiplied by m/2 and which characterizes the reliability of the transmission, to each symbol;
selecting the functional dependence of each weighting factor such that ##EQU3## demodulating the received data by first multiplying the symbol values of the symbols by the associated weighting factor (Wik, Wi'"'"'k'"'"') and then forming a linear combination of corresponding weighted symbol values to determine the received data.
1 Assignment
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Accused Products
Abstract
A method for the transmission of digital data by means of phase modulation (PSK) and "frequency hopping", in which symbols are transmitted several times in different transmission sections as synchronization information for coherent demodulation, and wherein weighting factors taking into consideration the existence and influence of a disturbance source are calculated for each symbol. The symbol values are multiplied by these weighting factors before the values of corresponding symbols are linearly combined and utilized for evaluation.
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Citations
4 Claims
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1. Method for demodulating received data modulated in a received data signal, said signal being composed of several transmission sections of fixed length, each transmission section having a fixed carrier frequency, which is changing in steps from one transmission section to the next and is modulated by means of m discrete permitted phase values by phase modulation of a carrier frequency, each transmission section containing the data in the form of a plurality of symbols and said signal containing the data to be transmitted plural times, including using different transmission sections for the same data, said method comprising the steps of:
-
determining for each transmission section a mean phase value (φ
i);determining the phase difference (Δ
φ
ik) between the symbol phase (φ
ik) and the mean phase value (φ
i) of the associated transmission section for each symbol within a transmission section;allocating a weighting factor (Wik, Wi'"'"'k'"'"') which functionally depends on the phase difference (Δ
φ
ik) multiplied by m/2 and which characterizes the reliability of the transmission, to each symbol;selecting the functional dependence of each weighting factor such that ##EQU3## demodulating the received data by first multiplying the symbol values of the symbols by the associated weighting factor (Wik, Wi'"'"'k'"'"') and then forming a linear combination of corresponding weighted symbol values to determine the received data. - View Dependent Claims (2, 3, 4)
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Specification