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A parallel OQPSK offset four -phase shift key control the demodulator

A four-phase phase-shift keying and demodulator technology, which is applied in the modulation carrier system, digital transmission system, electrical components, etc., can solve the problems that the logic operation cannot work normally and affect the normal operation of the demodulation system, so as to improve the frequency spectrum Efficiency and transmission efficiency, the effect of improving emission efficiency and high transmission rate

Active Publication Date: 2022-03-01
NO 54 INST OF CHINA ELECTRONICS SCI & TECH GRP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When the working clock of FPGA performs various demodulation algorithms at such a high rate, various logic operations of FPGA will not work normally, and eventually affect the normal operation of the demodulation system

Method used

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  • A parallel OQPSK offset four -phase shift key control the demodulator
  • A parallel OQPSK offset four -phase shift key control the demodulator
  • A parallel OQPSK offset four -phase shift key control the demodulator

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Embodiment Construction

[0034] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0035] Such as figure 1 As shown, a high-speed parallel OQPSK offset quadrature phase shift keying demodulator includes an AD sampling module 1 and a resampling module 2 based on FPGA, a frequency down conversion module 3, a frequency estimation module 4, a phase estimation module 5, Matched filter module 6, timing error estimation module 7, and frame search and decoding module 8, resampling module 2, down-conversion module 3, matched filter module 6, frame search and decoding module 8 are connected in sequence; wherein:

[0036] The sampling clock of the AD sampling module 1 is a symbol clock with a fixed frequency, which is used to change the baseband analog signal into a 4-times-sampled OQPSK signal with 4 channels of parallel I and Q, and send each signal together with the sampling clock to the re-sampling module 2;

[0037]The frequency estimation modu...

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Abstract

The invention discloses a high-speed parallel OQPSK offset four-phase phase-shift keying demodulator, which belongs to the technical field of OQPSK. It includes an AD sampling module, a resampling module, a down-conversion module, a frequency estimation module, a phase estimation module, a matched filter module, a timing error estimation module, a frame search and decoding module. All the modules in the present invention work in parallel mode. When working, the baseband signal is first AD sampled, and the frequency estimation and phase estimation are sent to the down-conversion module through the frequency offset compensation loop and the carrier phase synchronization loop. After the frequency conversion module completes the large frequency offset and phase offset compensation of the system, the output signal of the matched filter module is used to complete the OQPSK timing recovery through the timing error estimation module and the resampling module to find the best sampling point. Finally, through frame search and decoding After the module finds the encoded frame header, it completes the LDPC decoding and realizes the demodulation of the high-speed parallel OQPSK modulation mode. The invention transmits a large amount of information, and is especially suitable for nonlinear band-limited channels.

Description

technical field [0001] The present invention relates to the technical field of OQPSK offset quadrature phase shift keying, in particular to a high-speed parallel OQPSK offset quadrature phase shift keying demodulator, which can be used for a communication transmission system with a large amount of transmitted information and exhibiting nonlinear characteristics . Background technique [0002] QPSK (Quadrature Phase Shift Keying, Quadrature Phase Shift Keying) is a digital modulation method, which has a 180° phase jump between symbols. In order to avoid this phase jump, the prior art has developed OQPSK (Offset-QPSK, offset quadrature phase shift keying) modulation method. [0003] OQPSK modulation divides the input code stream into I and Q two paths, among which, the Q path is delayed by half a symbol period, and then carries out quadrature modulation. Therefore, at each phase conversion, only one signal may undergo phase polarity reversal, and the phenomenon of simultaneo...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/233
CPCH04L27/223H04L27/2334
Inventor 江会娟王少飞王立辉崔霞霞李新玲韩中良刘一龙
Owner NO 54 INST OF CHINA ELECTRONICS SCI & TECH GRP