Improving 3GPP-LTE Uplink Control Signaling Performance Using Complex-Field Coding

We study the uplink control signaling in Third-Generation Partnership Program (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 for different cases of channel state information (CSI) and noise variance information at the receiver. With a single receive antenna, the proposed method offers significant gains compared with the coding currently used in 3GPP-LTE for all the different scenarios considered in this work. However, the gains are relatively less with two receive antennas.