An achievable rate region for the asynchronous multiple access channel with feedback is established through the use of superposition coding, list decoding and time sharing. The calculation results demonstrate that lac...An achievable rate region for the asynchronous multiple access channel with feedback is established through the use of superposition coding, list decoding and time sharing. The calculation results demonstrate that lack of synchronization does not affect the achievable rate region when the code block length tends to infinity, and that if the length of the code word is finite, especially not sufficiently larger than a fixed maximal delay, the asynchronization will cause a loss of the rate region. The amount of such a loss with its explanation for the reason is given, and the difference between the losses for the asynchronous multiple access channel with and without feedback is also discussed in this paper.展开更多
We study the optimal precoding for a full-duplex (FD) system, where one FD multi-antenna base station (BS) respectively transmits to and receives from two half-duplex single-antenna mobile users (MUs) on the same time...We study the optimal precoding for a full-duplex (FD) system, where one FD multi-antenna base station (BS) respectively transmits to and receives from two half-duplex single-antenna mobile users (MUs) on the same time slot and frequency band. At the FD BS, the received signal from the desired MU is severely affected by the extremely strong self-interference (SI) from its transmit antennas to the receive antennas. In the presence of residual SI after imperfect SI cancellation, the downlink transmission rate maximization problem subject to a targeted uplink rate is formulated as a non-convex optimization problem to characterize the achievable rate region for the considered system. Considering the case in which the SI channel is strongly correlated, the above problem is transformed into a convex problem by exploiting the rank-one property of the SI channel, which can be solved efficiently. Finally, numerical results validate the effectiveness of the proposed scheme.展开更多
文摘An achievable rate region for the asynchronous multiple access channel with feedback is established through the use of superposition coding, list decoding and time sharing. The calculation results demonstrate that lack of synchronization does not affect the achievable rate region when the code block length tends to infinity, and that if the length of the code word is finite, especially not sufficiently larger than a fixed maximal delay, the asynchronization will cause a loss of the rate region. The amount of such a loss with its explanation for the reason is given, and the difference between the losses for the asynchronous multiple access channel with and without feedback is also discussed in this paper.
基金supported by the National Natural Science Foundation of China(Nos.61401030 and 61501093)
文摘We study the optimal precoding for a full-duplex (FD) system, where one FD multi-antenna base station (BS) respectively transmits to and receives from two half-duplex single-antenna mobile users (MUs) on the same time slot and frequency band. At the FD BS, the received signal from the desired MU is severely affected by the extremely strong self-interference (SI) from its transmit antennas to the receive antennas. In the presence of residual SI after imperfect SI cancellation, the downlink transmission rate maximization problem subject to a targeted uplink rate is formulated as a non-convex optimization problem to characterize the achievable rate region for the considered system. Considering the case in which the SI channel is strongly correlated, the above problem is transformed into a convex problem by exploiting the rank-one property of the SI channel, which can be solved efficiently. Finally, numerical results validate the effectiveness of the proposed scheme.
