Performance of fractional delay estimation in joint estimation algorithm dedicated to digital Tx leakage compensation in FDD transceivers

Abstract

This paper deals with the performance of the fractional delay estimator in the joint complex amplitude/delay estimation algorithm dedicated to digital Tx leakage compensation in FDD transceivers. Such transceivers suffer from transmitter-receiver signal leakage. Combined with non linearity of components in the receiver path, the baseband received signal is impaired by a baseband polluting signal. This baseband polluting term depends on the equivalent Tx leakage channel which models leakages of the receiver path. In (Gerzaguet et al., Digit. Signal Proc 51:35-46, 2016), we have proposed a Tx leakage interference cancellation algorithm based on joint estimation of the complex gain and the fractional delay of the equivalent Tx leakage channel and we have derived the asymptotic performance of the complex gain estimator, that showed the necessity of the fractional delay estimation. In this paper, we propose a comprehensive study of the fractional delay estimation algorithm and its analytic performance. The study is based on the analysis of the S-curve and loop noise variance of the timing error detector, from which an approximation of the asymptotic performance of the joint estimation algorithm is derived.

Physical Layer Famous Waveform Approaches for Fifth Generation Cellular Network

“…First we start with the generalized frequency division multiplexing (GFDM), it is a non-orthogonal, digital multicarrier transmission scheme proposed to address emerging requirements in cellular communications systems [5].…”

“…GFDM is a multi-carrier system, which digitally implements the classical filter band approach. Cyclic prefix (CP) insertion is used to allow for low complex equalization at the receiver side [5].…”

“…IDFT) a precoding stage can be inserted before the IFFT (resp. after FFT), leading to the so-called single carrier frequency division multiple access (SC-FDMA) used in the uplink of 3GPP-LTE [5].…”

“…The idea is to admit some crosstalk or interference, and to control these impairments by a suitable transceiver structure and transmission technique. To address these design goals various signal design techniques are used [5].…”