Algorithm for cell search in OFDMA downlink

One essential stage in Orthogonal frequency-division multiple access (OFDMA) downlink (DL) is cell search, which is the initialization for user´s access to Base Station (BS). This paper proposes an advanced cell search preamble frequency structure based on Constant Amplitude Zero Auto-Correlation (CAZAC) sequence. This scheme spends much lower computational complexity than the conventional cell search method, while efficient cell search performance is achieved. From the result of simulation, this modified preamble structure effectively enhances the user´s capability of cell identification, especially for users at the cell boundary even with low SNR.