摘要
To reduce energy consumption while maintaining users＇ Quality of Service （QoS） in Orthogonal Frequency Division Mul- tiplex Access （OFDMA） relay-enhanced net- works, an adaptive energy saving subcarrier, bit and power allocation scheme is presented. The optimal subcarrier, bit and power alloca- tion problems based on discrete adaptive modula- tion and coding scheme have been previously formulated for relay-enhanced networks, and have been reformulated into and solved by integer programming in optimization theory. If the system still has a surplus of subcarriers after resource allocation, we carry out Band- width Exchange （BE） to enable more subcar- riers to participate in transmission to save en- ergy. In addition, as the relay selection scheme is closely linked with heuristic energy saving resource allocation, a relay selection scheme is proposed. Simulation results indicate that the proposed algorithm consumes less energy when transmitting the same number of bits than greedy energy saving schemes, although its spectrum efficiency is worse.
To reduce energy consumption while maintaining users' Quality of Service (QoS) in Orthogonal Frequency Division Multiplex Access (OFDMA) relay-enhanced networks, an adaptive energy saving subcarrier, bit and power allocation scheme is presented. The optimal subcarrier, bit and power allocation problems based on discrete adaptive modulation and coding scheme have been previously formulated for relay-enhanced networks, and have been reformulated into and solved by integer programming in optimization theory. If the system still has a surplus of subcarriers after resource allocation, we carry out Band- width Exchange (BE) to enable more subcarriers to participate in transmission to save energy. In addition, as the relay selection scheme is closely linked with resource allocation, a heuristic energy saving relay selection scheme is proposed. Simulation results indicate that the proposed algorithm consumes less energy when transmitting the same number of bits than greedy energy saving schemes, although its spectrum efficiency is worse.
基金
supported partially by the 973 Program under Grant No. 2012CB316100
National Natural Science Foundation of China under Grants No. 61071108, No. 61032002
the Central Universities Basic Scientific Research Special Fund under Grant No.SWJTU12CX097
