MC-CDMA COMMUNICATION SYSTEM, BASE STATION APPARATUS, AND RECEIVER

摘要

PROBLEM TO BE SOLVED: To provide a carrier frequency synchronizing method with high accuracy and having a wide detection range.

SOLUTION: A base station in an MC-CDMA communication system transmits pilot symbols with a pattern as shown in A in Fig. (a) by each subcarrier. An up-converter 45 in a receiver applies up-conversion to the pattern A in a received signal by two subcarriers to obtain a pattern shown in B in Fig. (a), an adder 44 calculates (A+B) to obtain a signal with a pattern C wherein odd number subcarriers are cancelled out. Since this signal includes no components of the odd number subcarriers as to the pilot symbols, the first and latter halves of 1 OFDM symbol show the same waveform. A correlation arithmetic section 46 calculates the correlation between the signal with the pattern C and a signal resulting from delaying the signal with the pattern C at a delay section 47 by a 1/2 symbol to estimate a frequency offset by the 1/2 symbol and controls a VCO 51.

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