Deriving a Joint Interference Detection and Channel Estimation for WB-OFDM from EM-MAP Theory

Abstract

For modern wideband transmission systems narrowband interference and their identification becomes an important issue especially for weak interferers. This paper theoretically derives an interference detection scheme from EM theory in conjunction with a MAP channel estimation. The approach is related to a previously introduced heuristic scheme [1] and does not require mute periods or carriers, but works on a known burst preamble. Beyond the derivation of the detector-estimator, this work analytically evaluate the estimator variance, showing the value of the scheme.

A Comprehensive Study of Channel Estimation for WBAN-based Healthcare Systems: Feasibility of Using Multiband UWB

“…From (23), we see that the number of multiplications to find AR process is N þ N ¼ 2»N . Conversely, (25) implies that computational complexity of expected current estimation and predicted estimation are the same. Suppose, the complexity of predicted estimation is M then (24) provides the complexity of current channel estimation; it equals M þ 2»N þ M ¼ 2»M þ 2»N .…”

“…A multistage approach is proposed in [25], where the narrowband interference (NBI) detector is combined with channel estimator. A similar idea is visited in [26] but based on Expectation-Minimization (EM) theory.…”

Wideband interference in pilot symbol assisted OFDM systems

“…Recently, the susceptibility of pilot symbol assisted systems to narrowband interference has received significant attention, for example [3][4][5][6][7][8]. These papers show that narrowband interference degrades the performance of both the common Schmidl-Cox [9] pilot symbol detector and the common Moose [10] synchronizer.…”

“…These papers show that narrowband interference degrades the performance of both the common Schmidl-Cox [9] pilot symbol detector and the common Moose [10] synchronizer. Examples of narrowband interferers considered in [3][4][5][6][7][8] include cordless telephones, baby monitors and garage door openers. While the definition of "narrowband" varies between the cited papers, attention typically has focused on interference which occupies no more than 5% of the OFDM system bandwidth and affects only a few OFDM subcarriers.…”

Suppression of Strong Interference in UWB

“…In [3], [4], [5] analog filters have been proposed to suppress the NBI. Digital interference suppression has been proposed in [6], [7] and [8]. As proposed in [9] we use both analog and digital interference suppression filters, since only analog or only digital suppression is inadequate.…”