A transmission system and method of the mobile digital multimedia broadcast signals

Abstract

The disclosed transmission system for mobile digital multimedia broadcast signal comprises: a channel coder to receive, code and interlace data flow to transform it into bit flow; a constellation mapper to map the bit flow into QAM, BPSK or QPSK signal flow; an OFDM signal forming module to insert the continual and discrete pilot frequency into last signal flow and load on the service sub-carrierto form OFDM signal; a framing module to add beacon into the OFDM signal and form transmission frame; and an up-conversion module to generate RF signal for transmission. It also discloses corresponding transmission and allocation method.

Description

technical field

[0001] The invention relates to the field of mobile digital multimedia broadcasting, in particular to a signal transmission system and method in mobile digital multimedia broadcasting. technical background

[0002] Orthogonal Frequency Division Multiplexing (OFDM) is a well-known multi-carrier modulation method. Its main idea is to divide the channel into several orthogonal sub-channels, convert high-speed data signals into parallel low-speed sub-data streams, and modulate to transmission on sub-channels. Orthogonal signals can be separated by using correlation techniques at the receiving end, which can reduce the mutual interference ICI between sub-channels. The signal bandwidth on each sub-channel is smaller than the correlation bandwidth of the channel, so each sub-channel can be regarded as flat fading, so that inter-symbol interference can be eliminated. And since the bandwidth of each sub-channel is only a small part of the original channel bandwidth,...

Examples

Embodiment approach

[0082] According to another aspect of the present invention, the present invention proposes an implementation manner of a mobile digital multimedia broadcasting signal transmission method. The mobile digital multimedia broadcasting signal transmission method includes: a) receiving a data stream and transmitting the data stream Converting to a bit stream after encoding and interleaving; b) mapping the bit stream output by the channel encoder to a symbol stream in QAM, BPSK or QPSK mode; c) inserting scattered pilots and continuous pilots into the output of the constellation mapper After the symbol flow, it is loaded into effective subcarriers to form OFDM symbols. The corresponding relationship between the subcarriers, data and pilots of the OFDM symbol forming module is: (1) the effective subcarrier numbers are 0~3075 (when the channel bandwidth is 8MHz ) or 0 to 627 (when the channel bandwidth is 2MHz); (2) Insert scattered pilots, in even OFDM symbols (starting from 0), the n...

technical field

[0001] The invention relates to the field of mobile digital multimedia broadcasting, in particular to a signal transmission system and method in mobile digital multimedia broadcasting. technical background

[0002] Orthogonal Frequency Division Multiplexing (OFDM) is a well-known multi-carrier modulation method. Its main idea is to divide the channel into several orthogonal sub-channels, convert high-speed data signals into parallel low-speed sub-data streams, and modulate to transmission on sub-channels. Orthogonal signals can be separated by using correlation techniques at the receiving end, which can reduce the mutual interference ICI between sub-channels. The signal bandwidth on each sub-channel is smaller than the correlation bandwidth of the channel, so each sub-channel can be regarded as flat fading, so that inter-symbol interference can be eliminated. And since the bandwidth of each sub-channel is only a small part of the original channel bandwidth,...

Examples

Embodiment approach

[0082] According to another aspect of the present invention, the present invention proposes an implementation manner of a mobile digital multimedia broadcasting signal transmission method. The mobile digital multimedia broadcasting signal transmission method includes: a) receiving a data stream and transmitting the data stream Converting to a bit stream after encoding and interleaving; b) mapping the bit stream output by the channel encoder to a symbol stream in QAM, BPSK or QPSK mode; c) inserting scattered pilots and continuous pilots into the output of the constellation mapper After the symbol flow, it is loaded into effective subcarriers to form OFDM symbols. The corresponding relationship between the subcarriers, data and pilots of the OFDM symbol forming module is: (1) the effective subcarrier numbers are 0~3075 (when the channel bandwidth is 8MHz ) or 0 to 627 (when the channel bandwidth is 2MHz); (2) Insert scattered pilots, in even OFDM symbols (starting from 0), the n...

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