Tumula V. K. Chaitanya

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—We consider the optimization of power in in-cremental redundancy (IR) based hybrid automatic repeat request (HARQ) schemes when the maximum number of (re)transmissions is fixed. We formulate two optimization problems: (i) minimizing the packet drop probability (PDP) under a total average transmit power constraint, and (ii) minimizing the average transmit(More)
—We consider the optimization of Chase combining (CC)-based hybrid-automatic repeat request (HARQ) schemes with a limit on the maximum number of retransmissions. We formulate two optimization problems: (i) minimizing the packet drop probability (PDP) under a total average transmit power constraint, and (ii) minimizing the average transmit power under a(More)
—We study the uplink control signaling in 3GPP-Long Term Evolution (LTE) systems. Specifically, we propose a precoding method that uses complex-field coding (CFC) to improve the performance of the PUCCH format 2 control signaling. In the case of perfect channel state information (CSI) at the receiver and with a single receive antenna, the proposed method(More)
—We present a retransmission scheme based on su-perposition modulation for the symmetric relaying scenario when the number of retransmissions for a data packet is limited. We consider both diversity combining based as well as code combining based retransmission schemes. Under the assumption that the receiver implements a mechanism that can use all(More)
—We study the uplink control signaling in 3GPP-Long Term Evolution (LTE) systems. Specifically, we propose a precoding method that uses complex-field coding (CFC) to improve the performance of the physical uplink control channel (PUCCH) format 2 control signaling. We derive optimal detectors for both the conventional method and the proposed precoding method(More)
—In this paper, we study retransmission strategies for the symmetric relaying scenario when the number of retransmis-sions for a data packet is limited. We propose a retransmission scheme based on superposition modulation and give the exact packet drop probability expression for it when only one retrans-mission is allowed. We compare the performance of the(More)
—We propose improvements for the physical uplink control channel (PUCCH) format 2 control signaling in 3GPP-LTE systems. These improvements can be useful for low-cost UE design and optimization planned for the future LTE releases. In the proposed method, instead of repeating a single QPSK symbol across the 12 subcarriers in each OFDM symbol of a resource(More)