A Method for Improving the Receiving Performance of Differential System

Abstract

The invention discloses a method of improving differential system receiving performance, which comprises signal modulation and signal demodulation. The signal modulation step includes the following steps of (a) data inputting; (b) differential modulation; (c) time frequency transformation; and (d) data analog conversion. The data demodulation step includes the following steps of (S1) signal inputting; (S2) sampling and frequency correcting; (S3) signal extracting and time frequency transforming; (S4) differential demodulating; and (S5) signal outputting. In the step S3, signal extraction and time frequency transformation are simultaneously performed on synchronous modules. The step S4 further includes the following steps of (S41) performing channel estimation by using reference data; and (S42) performing demodulation by using the channel estimated value. By using the reference data for channel extraction and white noise estimation, the method makes the noise of each data block reduced after the demodulation process. The system receiving performance is greatly improved. Meanwhile, by using a decision feedback means, the method makes the system performance guaranteed to the maximum.

Description

technical field [0001] The invention relates to the technical field of communication, in particular to a method for improving the receiving performance of a differential system. Background technique [0002] In the current communication field, the differential modulation method is widely used in many communication systems because of its simplicity of implementation. Differential modulation means that each characteristic state of the digital modulation signal is expressed by the value of the characteristic value of the modulated signal relative to the given specific change of the previous signal element. However, since this type of system uses the correlation between the front and rear data, in the demodulation process, not only the interference signal of this data block is introduced, but also the interference signal of its reference data block is introduced. If no further processing , it will cause the performance of this type of system to be 3dB worse than that of the non...

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Problems solved by technology

However, since this type of system uses the correlation between the front and rear data, in the demodulation process, not only the interference signal of this data block is introduced, but also the interference signal of its reference data block is introduced. If no further processing , it will cause the performance of this type of system to be 3dB worse than that of the non-coherent demodulation system. In practical applications, this 3dB difference will greatly reduce the actual transmission effect of the system.

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