Delay Estimation for Ranging and Localization Using Multiband Channel State Information

In wireless networks, an essential step for precise range-based localization is the high-resolution estimation of multipath channel delays. The resolution of traditional delay estimation algorithms is inversely proportional to the bandwidth of the training signals used for channel probing. Considering that typical training signals have limited...

Memory and computation reduction for least-square channel estimation of mobile OFDM systems

Mobile OFDM refers to OFDM systems with fast moving transceivers, contrastive to traditional OFDM systems whose transceivers are stationary or have a low velocity. In this paper, we use Basis Expansion Models (BEM) to model the time-variation of channels, based on which two least-squares (LS) channel estimators are presented. The first channel...

Equalization for multi-scale multi-lag OFDM channels

We consider an orthogonal frequency-division multiplexing (OFDM) transmission scheme over wideband underwater acoustic channels, where the propagation paths can experience distinct Doppler effects (manifested in signal scales) and time of arrivals (manifested in lags). We capture such an effect in this paper with a multi-scale multi-lag (MSML)...

MIMO-OFDM performance in relation to wideband channel properties

In this paper, the sensitivity of the error rate performance of MIMO-OFDM-based practical systems (WiMAX and LTE) to wide band channel properties is investigated. The behavior of the wideband channel is characterized in terms of delay spread (DS) and angular spread (AS). The impacts of DS and AS on the system performance are addressed with both...

Downlink Resource Allocation for Evolved UTRAN and WiMAX Cellular Systems

The future broadband wireless cellular systems evolved UTRAN (E-UTRAN) and WiMAX are receiving a lot of interest in recent years. Both systems deploy orthogonal frequency division multiplex (OFDM) physical layer consisting of large number of mutually orthogonal sub-carriers. This physical layer provides high robustness against multi-path effects...

Multiband OFDM for Covert Acoustic Communications

A multiband OFDM transmitter and receiver are presented for underwater communications at low SNR. Compared with a single-band OFDMscheme, the multiband approach leads to a considerable reduction in the receiver complexity. The proposed system has been tested at sea with 16 subbands covering a total bandwidth of 3.6 kHz, at user data rates of 4.2...

Covert Underwater Communications with Multiband OFDM

We consider the use of orthogonal frequency division multiplexing (OFDM) for covert acoustic telemetry. To reduce the complexity of the receiver we use a multiband approach, modulating each band by OFDM. The system has been tested at sea in a highly time-varying environment. A total bandwidth of 3.6 kHz was divided in 16 subbands. Data rates of...