A robust method to estimate SINR in LTE/LTE-A uplink control channel

In LTE/LTE-A (Long Term Evolution/ Long Term Evolution-Advanced) wireless technology, control signaling information in uplink like channel quality indicator (CQI), Acknowledgement (ACK/NACK) for Hybrid Automatic Request (HARQ), Scheduling Request (SR) from users equipment (UEs) to the Evolved Node Base-station(eNodeB) is carried over the Physical Uplink Control Channel (PUCCH). The PUCCH is a code-multiplexed narrow band channel where more than one user is multiplexed by means of orthogonal Code Division Multiplex (CDM) on the same set of sub-carriers. For optimum LTE system performance, the eNodeB must accurately estimate the SINR on the received PUCCH channel per-user and signal the UEs accordingly to transmit their PUCCH at an optimum power level, such that the received signal can be reliably decoded from multiple users typically even in the presence of receiver impairments like timing offset(TO) between users and eNodeB. This system performance should be guaranteed over a wide SINR (Signal-to-Interference-Noise Ratio). This paper establishes a robust method to estimate the PUCCH SINR for each allocated user in the presence of channel impairments.