Details

Autor(en) / Beteiligte

• Yang-Han Lee
• Hsien-Wei Tseng
• Liang-Yu Yen
• Yu-Lin Hsiao
• Jing-Shown Wu
• Hen-Wai Tsao

Titel

Carrier frequency offset detection using hierarchical modulations for OFDM communications

Ist Teil von

• 2012 International Symposium on Intelligent Signal Processing and Communications Systems, 2012, p.195-200

Ort / Verlag

IEEE

Erscheinungsjahr

2012

Quelle

IEEE Xplore

Beschreibungen/Notizen

• In this study, we used hierarchical modulation technology to estimate the carrier frequency offset (CFO) caused by the Doppler effect. In this study, we transformed modulation within orthogonal frequency-division multiplexing into hierarchical modulation. We estimated the extent of the Doppler effect using the hierarchical modulation characteristic that the bit error rate (BER) of each level varies for differing CFO. The design developed in this study estimates the CFO and conducts hierarchical modulation of pilot signals. The receiving end estimates the CFO based on the characteristic that the BER of each level has different error rates at various CFO degrees. The simulation result showed that the actual BER was higher than the mathematically analyzed BER for each level, which resulted in overestimated CFO degrees or extents.