OFDM transmission with single antenna interference cancellation

Abstract

Future mobile communications radio networks, e.g. 3GPP Long Term Evolution (LTE), will typically use an orthogonal frequency division multiplexing (OFDM) based air interface in the downlink. Furthermore, in order to avoid frequency planning, a frequency reuse factor of one is desirable. In this case, system capacity is limited by interference, which is particularly crucial for mobile terminals with a single receive antenna. For a high throughput, interference cancellation algorithms are required in the receiver. In this paper, a single antenna interference cancellation (SAIC) algorithm is introduced for amplitude-shift keying (ASK) modulation schemes used in coded OFDM transmission which achieves high gains in comparison to a conventional coded OFDM transmission employing quadrature amplitude modulation (QAM) in an interference limited scenario. Furthermore, an adaptive least-mean-square (LMS) and a recursive least-squares (RLS) SAIC receiver, respectively, are presented. We show that in particular the RLS solution enables a good tradeoff between performance and complexity and is robust even to multiple interferers and frequency synchronization errors.