Pilot‐Assisted Channel Estimation

Abstract Channel estimation is a challenging task in coherent wireless communications systems since it highly impacts data detection performance. To acquire channel state information, known pilot symbols are commonly inserted in the signal to be transmitted. Then, at the receiver, the channel is estimated comparing the received signal with the pilot symbols. Pilot symbol assisted modulation (PSAM) is a channel estimation technique commonly used, where known symbols are transmitted over dedicated resources and they are used as reference signals. PSAM spends valuable bandwidth to transmit the pilot signal in order to obtain low channel estimation error. Currently, 5G technologies have been using different versions of PSAM to estimate the channel and different patterns have been tested to improve the communication performance.