A Fast Bandwidth Request and Grant Method for IEEE 802.16 OFDMA/TDD Systems
In the design of a contention-based bandwidth request scheme, decrease in data transmission delay is the most important factor. This paper proposes a new CDMA-based bandwidth request method in which the bandwidth request code contains the channel quality information and amount of bandwidth required by a mobile station. A mobile station composes the bandwidth code according to the needed bandwidth and current channel situation. The base station allocates uplink bandwidth depending on the received code. Also, the proposed method adopts a negative acknowledgement method that determines whether a transmitted code has been successfully detected by the base station.