Parameterized cancellation of partial-band partial-block-duration interference for underwater acoustic OFDM

Abstract

Despite that underwater acoustic channels are well known to contain various interferences, research on interference mitigation in underwater acoustic communications has been very limited. In this paper, we deal with a wideband orthogonal frequency division multiplexing (OFDM) transmission in the presence of an external interference which occupies partially the signal band and whose time duration is shorter than the OFDM block. We parameterize the unknown interference waveform by a number of parameters assuming prior knowledge of its frequency band and time duration, and develop an iterative receiver, which couples interference detection via a generalized likelihood-ratio-test (GLRT), interference reconstruction and cancellation, channel estimation, and data detection. In addition to simulation results, we verify the receiver performance using data sets collected from two experiments. In both time-invariant and time-varying channels, the proposed iterative receiver achieves robust performance in the presence of unknown interference.

The Algorithm of the Clutter and Interference Deletion Based on the Image Technique of the Group Segmentation

“…Compared with the traditional multi-target, track maintenance of the targets in formation is more complicated, and the existing algorithms of formation targets tracking are mostly based on the overall formation tracking without considering the problem of targets tracking in a formation; while the tracking environment of track maintenance of the targets in a formation is relatively single in some algorithms, which is difficult to apply to the complex background such as cloud-rain clutter [1][2][3][4], banded interference [5][6][7][8][9] and so on. To solve this problem, the characteristics of targets in a formation is mainly discussed in this paper.…”

Leveraging spatial diversity to mitigate partial band interference in undersea networks through waveform reconstruction

“…In pane (a), the data packet was received without interference and successfully decoded in as well as the channel conditions. While successful steps to mitigate interference have recently been reported [2], utilizing the spatial diversity implicit in the undersea network to mitigate interference has not yet been attempted.…”

“…The work in [2] developed a single receiver algorithm to mitigate partial band interference. Building upon this work, we seek to develop a spatial receiver for underwater networks which takes advantage of the geographical separation of the hydrophones resulting in the interference arriving at different times and lasting for different durations in the received signal.…”

A Comparison of a Single Receiver and a Multi-Receiver Techniques to Mitigate Partial Band Interference

“…The degradation in the received signal is highly variable, depending on the relative position of the interfering signals, information source and receivers as well as the channel conditions. Successful steps to mitigate interference using a single receiver have been reported in [2], and the potential of using multiple receivers to mitigate interference was demonstrated in [3]. The motivation behind this work is to compare the potential benefits that each mitigation strategy provides.…”

“…The work in [2] developed a single receiver parameterized interference cancellation (PIC) algorithm to mitigate partial band interference through a representation of the interference based on a rough estimate of its time duration and bandwidth. The PIC algorithm explicitly cancelled the interference without information loss or performance degradation caused by approximations.…”