Method for estimating roll-off coefficient of forming filter

Abstract

The invention discloses a method for estimating the roll-off coefficient of a forming filter, and the method comprises the following main steps: firstly, estimating the power spectral density P(l) of discrete complex baseband signals s(m); obtaining the value Pf(k) of the power spectral density P(l) in a discrete frequency interval f by normalizing the Pf(k); then, determining a search step delta alpha=0.9 / M; computing alpha=0.1+k delta alpha; obtaining the value H alpha f(k) of the corresponding H(f) in the discrete frequency interval f according to different alpha; obtaining a construction cost function J alpha by normalizing all the H alpha f(k); and obtaining the roll-off coefficients by estimation. In the method disclosed by the invention, under the premise that the carrier frequency and the symbol velocity are accurately estimated, the roll-off coefficients of the single carrier digital modulation signals of a root rise cosine forming filter are adopted for estimation, so that the method has the advantages of simple principle, high estimation accuracy and no reference to complicated algorithm, is convenient for hardware realization and can be applied to the fields of non-collaborative signal analysis, intelligent communication and the like.

Description

technical field [0001] The invention relates to a method for estimating the roll-off coefficient of a shaping filter, in particular to a method for estimating the roll-off coefficient of a square root raised cosine shaping filter. Background technique [0002] The square root raised cosine shaping filter is widely used in digital communication systems. Its advantages are: on the one hand, the receiving end can use the same filter to achieve matched filtering. This transceiver system has become a common system in digital communication systems; Different roll-off coefficients can be used according to channel characteristics to take into account both channel utilization and signal quality. [0003] In some cases, such as non-cooperative communication, for the receiver, the roll-off coefficient of the shaping filter of the sender is unknown, and in order to perform matched filtering, a certain roll-off coefficient must be selected. The current general method is to select a fixe...

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Problems solved by technology

[0004] At present, there are few publicly available methods for estimating the roll-off coefficient of the shaping filter. There are two main methods: one method is to indirectly estimate the roll-off coefficient of the shaping filter according to the relationship between the bandwidth, the shaping coefficient and the symbol rate. It is difficult to guarantee, so the performance of this method is not very ideal; another method is to extract the key point parameters according to the relationship between the baseband signal waveform and the impulse response function of the square root raised cosine shaping filter, and use the look-up table method to estimate, because the baseband signal The waveform is easily affected by noise and this method is not very accurate

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