Multiplex apparatus and multiplex method

Abstract

The invention relates to a multiplex device and a multiplex method that support energy diffusion; the multiplex device comprises a multiplexer and an energy diffuser. The multiplexer multiplexes various data information into different logic channels to form a multiplex frame which comprises a multiplex frame header, a multiplex frame payload and a filling part. The energy diffuser conducts energydiffusion treatment to the filling part to randomize the data in the filling part. The multiplex device and the multiplex method that support energy diffusion of the invention can enhance the transmitting power of a CMMB transmitting system under the modulation of 16QAM, thus increasing the effective covering scope of a transmitting tower.

Description

technical field [0001] The invention relates to a mobile multimedia broadcasting technology, in particular to a multiplexing device and multiplexing method supporting energy diffusion. Background technique [0002] In the front-end system of CMMB mobile multimedia broadcasting, the function of the multiplexer is to complete the encapsulation and arrangement of audio, video, data, electronic service guide and other information, so that it can be transmitted on the mobile multimedia broadcasting channel. The output of the CMMB multiplexer is the multiplexing frame of each logical channel, carrying the corresponding service data. According to the CMMB standard, such as figure 1 As shown, a multiplexed frame is composed of a multiplexed frame header, a multiplexed frame payload and a padding part, wherein the padding part is filled with 0xFF (that is, a "1111..." character string). [0003] In the way of 16QAM constellation mapping, the power corresponding to the 16 constellat...

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Problems solved by technology

[0005] However, from CMMB Standard Part 1 (CY / T 220.1-2006 Mobile Multimedia Broadcasting Part 1: Broadcast Channel Frame Structure, Channel Coding and Modulation) Page 5 figure 2 It can be seen from the physical layer functional block diagram shown in CMMB system that the physical layer stipulates that the scrambling process is performed after the constellation mapping. Therefore, in the 16QAM modulation mode, the effective data length of the multiplexing frame is relatively small When the short and filling part account for a large proportion of the entire multiplexing frame capacity, the distribution of "1" and "0" in the bit stream of the entire multiplexing frame is not random, resulting in a high probability of being mapped to each constellation point Not the same, resulting in a significant drop in the transmission power of the CMMB transmission system

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