Admission control and resource allocation in a heterogeneous OFDMA wireless network
IEEE Transactions on Wireless Communications
| Hi-index | 0.00 |
An elegant means by which high-speed burst wireless transmission can be accomplished with small amounts of overhead is through a novel technique referred to as clustered-OFDM (Cimini et al., 1996). By using OFDM modulation with a long symbol interval, clustered-OFDM overcomes the complex and costly equalization requirements associated with single carrier systems. Moreover, the need for highly linear power amplifiers typically required in OFDM systems is alleviated through the use of multiple transmit antennas combined with nonlinear coding. The clustering technique also leads to a natural implementation of transmit diversity. This paper reports on preliminary results on the performance of a clustered-OFDM system as well as the design and implementation of a clustered-OFDM transmitter. The prototype transmitter can deliver 7.5 Mbps, and it is expected that this data rate could be easily tripled with existing technology in a second generation system. The paper also describes the architectural trade-offs made in order to reduce the hardware complexity of the boards as well as some experimental results showing the operation of the transmitter.