Beacon transmitting method in mobile multimedia broadcasting system

Abstract

The invention discloses a beacon sending method of a mobile multimedia broadcast system and the beacon comprises a synchronous signal sequence. The method comprises the following steps that: (1) The synchronous signal sequence is generated; (2) Some of a continuous sequence is selected from an endposition of the synchronous signal sequence towards the front direction and is copied as a first cyclic prefix sequence; (3) According to the first cyclic prefix sequence, a second cyclic prefix sequence is gotten and a fixed corresponding relationship is formed between the second cyclic prefix sequence and the first cyclic prefix sequence; (4) When a beacon signal is transmitted, firstly the second cyclic prefix sequence is transmitted then the first cyclic prefix sequence and finally the synchronous signal sequence is transmitted. The beacon signal method of the invention increases the exactness of an initial synchronization and improves a searching range of a channel time domain impulsion response. When the channel time domain impulsion response is acquired, the invention can solve the problem that a larger wireless channel extends for a channel delay.

Description

technical field The invention relates to the technical field of mobile multimedia broadcasting, in particular to a beacon sending method in a mobile multimedia broadcasting system. Background technique In the mobile multimedia broadcasting system, the transmitter often sends a beacon signal, and then the receiver can firstly detect the starting position of the beacon through autocorrelation calculation, and obtain initial synchronization; then, use the local beacon sequence and the receiver The cross-correlation operation is performed on the received beacon sequence to obtain the time-domain impulse response of the channel. In the mobile multimedia broadcasting industry standard GY / T220.1-2006 promulgated by the State Administration of Radio, Film and Television of China, the beacon signal sent by the transmitter has a specific structure. Referring to FIG. 1 , it is a schematic diagram of the application of the existing beacon structure in the GY / T 220.1-2006 standard. W...

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Problems solved by technology

In the GY / T220.1-2006 standard, the synchronization signal sequence used for cross-correlation calculations is relatively short. At the same time, when the beacon transmission method obtains the channel time-domain impulse response, it cannot cope with the wireless channel situation with large channel delay expansion.

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