Channel estimation performance for frequency hopped OFDM using embedded synchronization

In this work we study the effects of channel estimation/equalization on the BER performance of RF carrier frequency hopped OFDM (FH-OFDM) when using synchronization information that is embedded directly into the OFDM time-domain baseband sample stream. Embedded synchronization eliminates the need for dedicated preamble slots for signal acquisition/synchronization, thus providing potential for improved channel access efficiency. Assuming perfect synchronization of the unknown time-frequency offsets, demodulated bit error rate (BER) performance is evaluated in frequency selective fading channels. Superposition (embedding) of the sync information causes interference onto the OFDM data information, which must be removed for satisfactory BER performance. Consequently, embedded synchronization interference cancellation (EIC) is utilized, which requires accurate estimation of the channel state information. Using coherent 4QAM-OFDM and 16QAM-OFDM modulation, BER performance is evaluated using the COST207 multipath fading channel model with RF carrier frequency hopping.