SPEAKER: DHIVAGAR B (EE11S005)
Ever since the adoption of the Single Carrier – Frequency Division Multiple Access (SC-FDMA) scheme for the uplink in the Long Term Evolution (LTE) standard, there has been much interest in improved receiver algorithms for interference limited SC-FDMA links. Conventional Linear Minimum Mean Square Error (LMMSE) based receivers are fairly well studied in literature due to their reduced algorithmic complexity. With LTE pushing upto eight parallel streams over the same time-frequency resource , Successive Interference Cancellation (SIC) based turbo receivers (Turbo-SIC) have been proposed to tackle the multi-stream interference (MSI). As SC-FDMA also suffers from inter symbol interference (ISI) caused by the multi-path channel, Decision Feedback Equalizer (DFE) based receivers have been considered as an alternative to the LMMSE receiver. Our work investigates the existing DFE and Turbo-SIC based receiver architectures and proposes a novel DFE receiver for MIMO SC-FDMA links which is capable of addressing both ISI and MSI. We consider two variants of the receiver architecture namely, parallel interference cancellation with maximum likelihood detection (PIC-MLD) and ordered success interference cancellation (OSIC). Though simulations show that both the receivers perform better than the existing receivers and reach the Matched Filter Bound (MFB), the DFE-OSIC receiver converges faster to the MFB due to superior cancellation gains through the SIC principle.