Jaemin Kwak

Intelligent modified channel and frequency offset estimation schemes in future generation OFDM-based packet communication systems

The channel estimation and frequency offset estimation scheme for future generation orthogonal frequency division multiplexing (OFDM-) based intelligent packet communication systems are proposed. In the channel estimation scheme, we use additional 8 short training symbols besides 2 long training symbols for intelligently improving estimation performance. In the proposed frequency offset estimation scheme, we allocate intelligently different powers to the short and long training symbols while maintaining average power of overall preamble sequence. The preamble structure considered is based on the preamble specified in standardization group of IEEE802.11a for wireless local area network (WLAN) and IEEE802.11p for intelligent transportation systems (ITSs). From the simulation results, it is shown that the proposed intelligent estimation schemes can achieve better mean squared error (MSE) performance for channel and frequency offset estimation error than the conventional scheme. The proposed schemes can be used in designing for enhancing the performance of OFDM-based future generation intelligent communication network systems.

Unequal Preamble Power Allocation Scheme for Frequency Offset Estimation in OFDM Based Packet Communication Systems

In this paper, an frequency offset estimation scheme for orthogonal frequency division multiplexing (OFDM) based packet communication systems is proposed, in which allocated powers of the short training symbols and long training symbols are different while maintaining average power of overall preamble sequence. The preamble structure considered is based on the preamble specified in IEEE802.11a and IEEE802.11p standardization group. From the simulation results, it is shown that the proposed scheme can achieve better mean squared error (MSE) performance for frequency offset estimation error than the conventional scheme.