English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The principle of QPSK modulation and demodulation is described and the detailed explanation and theoretical on DDC, carrier synchronization and bit synchronization principle is analyzed. A QPSK digital demodulation structure based on FPGA is proposed after detailed theoretical derivation for Costas loop carrier synchronization module.The entire system is completed on a single FPGA and use the Verilog programming language in Modelsim platform to simulate its function. Finally, a system test platform is built and the demodulated pattern is observed by an oscilloscope. The test result shows that the designed system can meet the basic requirements. keyword-QPSK; digital demodulation; carrier synchronization ;symbol synchronization;FPGA

Research of All Digital Demodulation Technology for QPSK