Joint Method of Moments (JMoM) and Successive Moment Cancellation (SMC) Multiuser Time Synchronization for ZP-OFDM-Based Waveforms Applicable to Joint Communication and Sensing

It has been recently shown that zero padding (ZP)-orthogonal frequency-division multiplexing (OFDM) is a promising candidate for 6G wireless systems requiring joint communication and sensing. In this paper, we consider a multiuser uplink scenario where users are separated in power domain, i.e., non-orthogonal multiple access (NOMA), and use...

Load-Modulation-Based IMD3 Cancellation for Millimeter-Wave Class-B CMOS Power Amplifiers Achieving EVM < 1.2%

This letter presents a novel load-modulation-based 3rd-order intermodulation distortion (IMD3) cancellation technique for class-B CMOS power amplifiers (PAs). In a class-B PA, the IMD3 generated by the 3rd-order transconductance ( $g_{m3}$ ) and the gain compression have opposite signs, and thus, they can cancel each other at specific bias...

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...

Positioning in a Multipath Channel Using OFDM Signals with Carrier Phase Tracking

In developing a high accuracy terrestrial radio navigation system, as a complement to a global navigation satellite system (GNSS), it is recognized that the performance of time delay estimation is proportional to, and thereby limited by, the signal bandwidth. Given a possibly narrow signal bandwidth, the central carrier phase can,...

Sparse Signal Bands Selection for Precise Time-based Ranging in Terrestrial Positioning

Time-based ranging accuracy is inversely proportional to the signal bandwidth. A larger the signal bandwidth leads to a higher accuracy of time delay estimation, but more complex hardware is needed. Alternatively, we explore the idea of using multiple narrow signal bands (e.g., 10 MHz of each) to create a large virtual signal bandwidth, which...

Cooperative Wideband OFDM Communication

In this thesis, major attention is paid to cooperative diversity as an alternative way to achieve spatial diversity when the multiple antenna structure is not an option. By adopting the cooperative relay nodes to forward information, we can mitigate the fading effects, increase the capacity, lower the bit-error rate, increase the achievable...

Identifying time-varying channels with aid of pilots for MIMO-OFDM

In this paper, we consider pilot-aided channel estimation for orthogonal frequency division multiplexing (OFDM) systems with a multiple-input multiple-output setup. The channel is time varying due to Doppler effects and can be approximated by an oversampled complex exponential basis expansion model. We use a best linear unbiased estimator (BLUE)...

A Processing Technique for OFDM-Modulated Wideband Radar Signals

The orthogonal frequency division multiplexing (OFDM) is a multicarrier spread-spectrum technique which finds wide-spread use in communications. The OFDM pulse compression method that utilizes an OFDM communication signal for radar tasks has been developed and reported in this dissertation. Using the ambiguity function tool, the feasibility of...

An investigation on the sensitivity of wavelet packet modulation to time synchronization error

Wavelet Packet based Multi-Carrier Modulation (WPMCM) offers an alternative to the well-established OFDM as an efficient multicarrier modulation technique. It has the advantage of being a generic transmission scheme whose actual characteristics can be widely customized to fulfill several requirements and constraints of advanced communication...

Adaptive Baseband Processing Techniques for Cognitive Radio Systems

Cognitive Radio is a new paradigm in the wireless communications. It puts the intelligence and awareness dimension to the radio communication system. A Cognitive Radio system will be aware of the changing condition in its environment. The awareness in this thesis is related to the spectrum and the channel stipulation. By intelligent learning and...

Theoretical performance of reiterated LMMSE filtering and coded radar waveforms

Orthogonal frequency division multiplexing (OFDM) waveforms offer strong advantages for integrated communication and radar systems. However, they exhibit inherent high-range sidelobes after matched filtering when standard communication constellation symbols are used for the coding of the carriers. Consequently, they require filtering at the...

Cognitive Radio with Single Carrier TDCS and Multicarrier OFDM Approach with V-BLAST Receiver in Rayleigh Fading Channel

This article presents the performance comparison of TDCS and OFDM based cognitive radio for MIMO system using VBLAST receiver architecture to reconstruct the transmitted data. The interference avoidance performance in terms of BER and bitrate are improved by adding multiple antennas to the system and the use of V-BLAST technique at the receiver....

Shifted Known Symbol Padding for Efficient Data Communication in a WLAN Context

To allow for a computationally efficient equalization scheme for the frequency-selective transmission channels encountered in wireless local area network (WLAN) applications, cyclic prefix (CP) block transmission schemes have been proposed, such as single-carrier CP (SC-CP) and multi-carrier CP (MC-CP) transmission, also known as orthogonal...