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Self-adaptive demodulating method for multi-carrier system

An adaptive modulation and multi-carrier system technology, applied in the field of digital signal transmission, can solve the problem of invariable modulation mode of digital transmission system, achieve the effect of facilitating upgrade and expansion, and emphasizing programmability

Inactive Publication Date: 2012-08-22
SHANDONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] Aiming at the problem that the modulation mode of the digital transmission system is invariable, the present invention provides a method for adaptive modulation of a multi-carrier system that can change the modulation mode by changing parameters without changing the hardware structure

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  • Self-adaptive demodulating method for multi-carrier system
  • Self-adaptive demodulating method for multi-carrier system
  • Self-adaptive demodulating method for multi-carrier system

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Embodiment Construction

[0021] Such as figure 1 As shown, the input data is interleaved and mapped under the control of the control module, and then the pilot frequency and training sequence are inserted for IFFT modulation. The data interweaving and mapping modules work under the control of the control module. Control modules such as figure 2 As shown, the interleaving module is as image 3 , 4 As shown, the mapping module is as Figure 5 shown. The working principle of the control module is: control data is embedded through software figure 2 In the RAM, the RAM outputs the stored modulation control data sequentially under the control of the address signal. The modulation control data are consecutive 2 (QPSK), 4 (16QAM), 6 (64QAM), and 8 (256QAM). Under the control of the enable signal, the modulation control signal mod is output, the modulation control signal is continuously added, and the data after the continuous addition is divided by 16 to get the remainder, and the control signal index...

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Abstract

The invention discloses a self-adaptive demodulating method for a multi-carrier system. The method comprises the following steps that: for four modulation modes of QPSK, 16QAM, 64QAM and 256QAM, control signals C 2, 4, 6 and 8 are used respectively; the control signal C is saved in a random access memorizer RAM, and a control module outputs a signal mod and a signal index under the control of an address signal output by an IFFT; 8-bit source data processed in the RAM is converted into the 16-bit data under the control of the mod and the index, wherein when the conversion is performed, a frontbyte is at lower 8 bits, and a rear byte is at higher 8 bits; the 16-bit data is circularly intercepted into the 8-bit data under the control of the signal index according to the principle that every8 bits is taken as a group; the 8-bit data is mapped into I / Q two paths of data under the control of the signal mod; and the mapped data is added with auxiliary information and then is subjected to IFFT to finish the modulation. The method has the advantage of realizing different modulation modes by updating a hardware configuration structure.

Description

technical field [0001] The invention relates to a method for adaptive modulation of a multi-carrier system, and belongs to the technical field of digital signal transmission. Background technique [0002] A typical multi-carrier digital transmission system includes a transmitter and a receiver. Orthogonal Frequency Division Multiplexing (OFDM) is a typical multi-carrier modulation. OFDM digital modulation technology often encodes and modulates digital signals, and then adds necessary auxiliary information, such as training sequences, pilot signals, synchronization signal etc. The coded data is transformed in the frequency-time domain through an inverse fast Fourier transform (IFFT) (Inverse Fast Fourier Transform). At the receiving end, after synchronization, frequency offset recovery, and Fast Fourier Transform (FFT) to complete the time-frequency domain transformation, equalization, and demodulation, the data consistent with the sending end is recovered. [0003] At pre...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/26
Inventor 袁东风孙健刘朝娜
Owner SHANDONG UNIV