Anti-multipath interference system and method for multi-carrier receiver

Abstract

The invention discloses an anti-multipath interference system and method for a multi-carrier receiver. The system comprises a combined processing unit, a signal cyclic convolution reconstruction unit, a multipath estimated adjustment unit, an FFT and frequency-domain balancing unit, a de-interleaving unit and a decoding unit, wherein the combined processing unit is used for simultaneously eliminating interference of an ascertained sequence to an information frame by utilizing an ascertained sequence estimation channel and outputting an OFDM information frame having a zero filling guard interval; the signal cyclic convolution reconstruction unit is used for performing signal cyclic convolution reconstruction of received data by utilizing channel estimation information; the multipath estimated adjustment unit is convenient to have the optimal performances for both front path processing and rear path processing and is used for estimating multipath spread by using an FIR transversal filter having a limited length to the most extent; the FFT and frequency-domain balancing unit is used for realizing conversion from a time-domain signal to a frequency domain and frequency-domain balancing; the de-interleaving unit is used for completing signal de-interleaving and dispersing a long continuous error code in an expected error correction range; and the decoding unit is used for completing error correction processing of soft decoding. According to the invention, various multipath interferences, the lengths of which are less than the guard interval length, can be eliminated; and furthermore, overlong multipath interferences, the lengths of which are more than the guard interval length, can be effectively resisted.

Description

technical field [0001] The invention belongs to the technical field of digital information transmission, and in particular relates to a system and method for anti-multipath interference in a multi-carrier receiver using a finite-length definite sequence as a guard interval. Background technique [0002] In wireless communication channels, especially in terrestrial wireless TV broadcast transmission channels, there are various long-delay static and dynamic multipath interferences. In order to effectively resist multi-path interference, current wireless multi-carrier receiving systems insert guard interval sequences into transmitted signal frames. [0003] European standard DVB-T adopts OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) cyclic prefix structure, and inserts a guard interval as long as 224 microseconds, so that it can resist 0dB echo interference of nearly 224 microseconds. The national standard DTMB inserts a well-kno...

AI Technical Summary

Problems solved by technology

In order to maintain high transmission efficiency, a definite protection sequence of limited length is usually inserted into the signal frame. For example, the PN sequence inserted in the multi-carrier mode of the national standard DTMB can only reach 125 microseconds at most, although the PN (Pseudo -randomNoise, pseudo-random sequence) sequence joint processing, so that the delay length against multipath interference is not limited by the length of the guard interval, but it is not suitable for fast time-varying channels

In existing low-complexity digital receiving systems, multipath processing is usually limited within the guard interval length. When the actual multipath length is greater than the guard interval length, the system performance will be severely degraded (any multipath intensity greater than -12dB path expansion will affect system performance), so it is necessary to propose an effective solution

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