Analysis of QPSK transmitted-reference systems

The usage of an additional autocorrelation branch is proposed for the demodulation of transmitted reference signals, to both relax the demands on the hardware implementation and allow for QPSK-TR signalling. The proposed autocorrelation receiver is proven to perform a complex-valued autocorrelation. Based on this insight, a discrete-time equivalent system model is derived, including a statistical characterization of the system taking into account noise, as well as intra- and inter-symbol-interference (IISI). The performance of a fractionally sampled QPSK-TR system is presented, operating at different data rates in different environments.