Uplink Packet Synchronization of OFDMA Systems

In order to support high rate data transmission, orthogonal frequency division multiplexing (OFDM) technology uses broadband consisting of a large number of narrow band orthogonal subcarriers. To apply the OFDM technology to outdoor mobile applications, the limitation of the transmission power of mobile station (MS) and the detrimental effect due to the granularity of bandwidth assignment have to be taken account. Some of the current standards are introducing the orthogonal frequency division multiple access (OFDMA) to take advantage of enhanced spectral efficiency by the fine granularity of bandwidth assignment and the coverage extension by power concentration gain in the uplink. This paper analyzes the uplink packet synchronization of current OFDMA standard and proposes a new uplink packet synchronization method, which makes implementation simple and improves system throughput.