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Shortwave modulator/demodulator and modulation/demodulation method thereof

A modem, modulation and demodulation technology, applied in the field of shortwave modem and its modulation and demodulation, can solve the problem of single business support ability, etc., achieve the effect of fast speed, strong data processing ability, and fast processing speed

Inactive Publication Date: 2012-08-15
西安烽火电子科技有限责任公司
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Problems solved by technology

Only supports data business communication, with a single business support capability

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  • Shortwave modulator/demodulator and modulation/demodulation method thereof
  • Shortwave modulator/demodulator and modulation/demodulation method thereof
  • Shortwave modulator/demodulator and modulation/demodulation method thereof

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Embodiment Construction

[0031] LDPC (Low-Density Parity-Check Codes, that is, Low-Density Parity-Check Codes) coding technology improves the performance of short-wave modems. LDPC is a forward error correction code and a special linear block code, and its check matrix only contains a small number of non-zero elements. It is the sparsity of the check matrix H that ensures that the decoding complexity and the minimum code distance only increase linearly with the code length. LDPC code is a code with the strongest error correction ability in channel coding, and because its decoder has a simple structure and can obtain extremely high throughput with less resource consumption, it has a wide application prospect. Compared with other encoding methods, LDPC codes have performance close to Shannon's limit, and the decoding is simple, which is very suitable for hardware operation. Therefore, this system adopts LDPC codes with decoding performance close to Shannon limit as FEC (Forward Error Correction) error ...

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Abstract

The invention relates to the field of communication technologies and discloses a shortwave modulator / demodulator and a modulation / demodulation method thereof. The modulator / demodulator comprises a signal processing unit; the signal processing unit comprises a master DSP (Digital Signal Processor), a slave DSP and an FPGA (Field Programmable Gate Array); the master DSP is used for carrying out LDPC (Low-Density Parity-Check Codes) coding, interleaving, Walsh modulation and code scrambling on data services or acoustic codes, and then carrying out 8PSK (8 Phase Shift Keying) modulation, and modulated signals are transmitted through an additive Gaussian white noise channel and are subjected to synchronous detection, HF-RLS (High Frequency-Radio Link Set) algorithm, Turbo balancing, 8PSK demodulation, descrambling, Walsh demodulation and de-interleaving; the slave DSP finishes an acoustic code algorithm; and the FPGA is used for decoding LDPCs. According to the technical scheme adopted by the invention, technologies, such as the LDPC coding / decoding and the Turbo balancing, are adopted, and thus the bit error ratio is little under white noises; and an ARQ (Automatic Repeat reQuest) mode is adopted for data transmission, so that the error-free data transmission can be guaranteed.

Description

technical field [0001] The present invention relates to the technical field of communication, and more specifically relates to a short-wave modem and a modulation and demodulation method thereof. Background technique [0002] Shortwave communication is widely used in military and civilian communications due to its long communication distance, low cost and good invulnerability. With the rise of adaptive short-wave communication technology, the quality of short-wave communication has been greatly improved, and it has become an important means of long-distance wireless communication. However, the multi-path interference and fading of the short-wave channel are very serious, so it is very difficult to transmit large-capacity and high-speed data on the short-wave channel, and the bit error rate is high. [0003] The short-wave modem is a wireless data terminal specially designed for short-wave channels. It is used with short-wave radio stations to realize data transmission. Cur...

Claims

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Application Information

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IPC IPC(8): H04M11/06H04L27/00
Inventor 张健张雅慧谭文生葛亮杨磊刘琪田甜
Owner 西安烽火电子科技有限责任公司
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