In asynchronous code division multiple access (A-CDMA) systems transmitting over multipath channels, both intersymbol interference (ISI) as a result of interchip (ICI) and (MAI) cannot be easily eliminated. Although it is possible to design multiuser detectors that suppress MAI ISI, these often require explicit knowledge at least the desired users' signature waveform. Recently, Liu Xu (see Proc. 29th Asilomar Conf. Signals, Systems Computers, 1996) introduced blind estimation algorithm for...

The primary challenge of a cost-effective and low-complexity near-field millimeter-wave (mmWave) imaging system is to achieve high resolution with few antenna elements as possible. Multiple-input multiple-output (MIMO) radar using simultaneous operation spatially diverse transmit receive antennas good candidate increase the number available degrees freedom. On other hand, higher integration complexity extremely dense transceiver electronics limits use MIMO only solutions within relatively...

Discontinuous reception (DRX) saves battery power of user equipment (UE) usually at the expense potential increase in latency Long Term Evolution (LTE) networks. Therefore, an optimization is needed to find best tradeoff between and saving. In this paper, we first develop analytical model estimate saving achieved incurred by DRX mechanism for active background mobile traffic. A scheme then formulated maintain a balance these two performance parameters based on operator's preference...

Multiple-input multiple-output (MIMO) radars and synthetic aperture radar (SAR) techniques are well researched have been effectively combined for many imaging applications ranging from remote sensing to security. Despite numerous studies that apply MIMO concepts SAR imaging, the design process of a MIMO-SAR system is non-trivial, especially millimeter-wave (mmWave) systems. Many issues be carefully addressed. Besides, compared with conventional monostatic sampling schemes or MIMO-only...

Narrowband Internet of Things (NB-IoT) is a new technology being implemented into the Long-Term Evolution (LTE) standards to support machine-to-machine communications. Applications IoT are expected rapidly increase and expand many sectors. Increased number devices trying access medium with typically small data packets will overwhelm network. Cognitive radios coupled random strategies can help alleviate excessive collisions in network by attempts. On other hand, most do not have hardware...

In this article, we introduce a novel algorithm for efficient near-field synthetic aperture radar (SAR) imaging irregular scanning geometries. With the emergence of fifth-generation (5G) millimeter-wave (mmWave) devices, SAR is no longer confined to laboratory environments. Recent advances in positioning technology have attracted significant interest diverse set new applications mmWave imaging. However, many use cases, such as automotive-mounted imaging, unmanned aerial vehicle (UAV) and...

Recent progress in complementary metal-oxide semiconductor (CMOS) based frequency-modulated continuous-wave (FMCW) radars has made it possible to design low-cost and low-power millimeter-wave (mmWave) sensors. As a result, there is strong desire exploit the mmWave sensors wide range of imaging applications including medical, automotive, security. In this paper, we present high-resolution imager prototype that combines commercially available 77 GHz system-on-chip FMCW radar synthetic aperture...

In this paper, we investigate novel data collection and training techniques towards improving classification accuracy of non-moving (static) hand gestures using a convolutional neural network (CNN) frequency-modulated-continuous-wave (FMCW) millimeter-wave (mmWave) radars. Recently, non-contact pose static gesture recognition have received considerable attention in many applications ranging from human-computer interaction (HCI), augmented/virtual reality (AR/VR), even therapeutic range...

Integration of multi-chip cascaded multiple-input multiple-output (MIMO) millimeter-wave (mmWave) sensors with synthetic aperture radar (SAR) imaging will enable cost-effective and scalable solutions for a variety applications including security, automotive, surveillance. In this paper, the first three-dimensional (3-D) holographic MIMO-SAR system using mmWave is designed implemented. The challenges imposed by use in high-resolution systems are discussed. Especially, important signal...

This paper considers a novel approach to joint estimation of the velocity (or Doppler frequency) and Direction Arrival (DOA) targets by time division multiplexing (TDM) multiple-input multiple-output (MIMO) radars in automotive applications. The TDM MIMO create orthogonal probing signals (in domain) allocating transmitter separate slot. In this paper, we consider standard radar be one where transmitters are activated sequentially according their natural spatial order. drawback is coupling...

Vital signs such as respiration rate and pulse (heart rhythm) rates are very useful in determining health problems managing well-being. Heart measurement techniques have evolved from counting pulses to contact-based approaches electrocardiography (ECG) photoplethysmography (PPG). The current availability proliferation of low-cost easily integrable millimeter wave (mmWave) radar sensors make contact-free simultaneous detection weak vital sign signals highly promising. However, echoes...

Ranging solutions for Internet of Things (IoT) localization applications seek to provide high accuracy with low cost implementation. Among candidate IoT technologies that may fit this criterion, Bluetooth is a desirable choice as energy (BLE) support ubiquitous in modern smartphones, providing implementation costs and power consumption. Recent advancements BLE ranging technology employ the Multicarrier Phase Difference technique which takes two-way channel frequency response (CFR)...

In LTE networks, mobile applications and their higher data rate requirements are the latest phenomenon causing a tremendous need in power saving for devices. Discontinuous reception (DRX) is one of key mechanisms LTE. Since DRX saves battery user equipment usually at expense potential increase latency, an optimization needed to find best tradeoff between latency saving. this paper, we first develop analytical model estimate achieved incurred by operation. Then, scheme formulated maintain...

Energy detection has been adopted as an alternative spectrum sensing method for cognitive radios due to its low computational complexity and not requiring a priori information of the signal be detected. In this work, we analyze accuracy different energy detector models in approximating exact solution both AWGN Rayleigh channels. Our simulations show that all these have almost same performance Hence, conclude any one them can used represent detector's instead complicated fading Using Edell's...

The K user interference alignment scheme proposed by Cadambe and Jafar (CJ) achieves K/2 degrees of freedom for networks with frequency selective channels. In this paper, we provide two new algorithms that optimize the precoding subspaces which maximize data rate performance CJ while maintaining achievable freedom. One design is obtained as a global solution constrained convex (concave) optimization problem maximizes sum rate. other provides low complexity closed-form to maximization...

In this paper, we propose a maximum likelihood method for jointly estimating carrier frequency offset (CFO) and sampling (SFO) in receivers orthogonal division multiplexing signals. The proposed estimator exploits the fact that single source (such as crystal oscillator or voltage controlled oscillator) is typically used modern wireless to provide reference both clock radio synthesizers. CFO capable of large estimation range (i.e., more than half intercarrier spacing) without extending length...

Multiple-input-multiple-output (MIMO) millimeter-wave (mmWave) sensors for synthetic aperture radar (SAR) and inverse SAR (ISAR) address the fundamental challenges of cost-effectiveness scalability inherent to near-field imaging. In this paper, MIMO-ISAR mmWave imaging systems are discussed developed. The rotational ISAR (R-ISAR) regime investigated in paper requires rotating target at a constant radial distance from transceiver scanning along vertical track. Using 77GHz radar, high...

Three-dimensional (3-D) synthetic aperture radar (SAR) is widely used in many security and industrial applications requiring high-resolution imaging of concealed or occluded objects. The ability to resolve intricate 3-D targets essential the performance such depends directly on system bandwidth. However, because high-bandwidth systems face several prohibitive hurdles, an alternative solution operate multiple radars at distinct frequency bands fuse multiband signals. Current signal fusion...

CDMA systems commonly use aperiodic spreading codes to distribute a signal spectrum uniformly over the channel bandwidth and differentiate neighboring cell sites. receivers often suffer from interference due multipath fading. Blind estimation schemes cannot be used because they require periodic sequences. RAKE are used, but fully exploit rich structure of signals minimize interference. This paper presents an iterative technique estimate parameters which can serve as preprocessing step in...

Discontinuous reception (DRX) can be configured as a power saving mechanism for user equipment (UE) in connected mode the long term evolution advanced (LTE-A) network. Since DRX saves UE's battery usually at cost of increased latency, tradeoff between these two conflicting performance metrics are inevitable. parameters optimized either maximizing or minimizing latency based on applications running UE. In this paper, we first develop an analytical model to estimate achieved and incurred by...

In this paper, we introduce an innovative super resolution approach to emerging modes of near-field synthetic aperture radar (SAR) imaging. Recent research extends convolutional neural network (CNN) architectures from the optical electromagnetic domain achieve on images generated signaling. Specifically, imaging, a method for generating high-resolution by scanning across space create aperture, is interest due its high-fidelity spatial sensing capability, low cost devices, and large...

In this paper, we investigate the performance of spatial-temporal zero-forcing linear equalizer architectures for a single-carrier Massive MIMO uplink system under frequency-selective fading environment. We establish relationships between choosing length D and in terms degrees freedom signal-to-interference plus noise ratio (SINR). also present how parameters (number antennas M transmit signal-to-noise ratio) impact differently both single-cell systems multi-cell with perfect imperfect...

In this article, we propose a framework for contactless human-computer interaction (HCI) using novel tracking techniques based on deep learning-based super-resolution and algorithms. Our system offers unprecedented high-resolution of hand position motion characteristics by leveraging spatial temporal features embedded in the reflected radar waveform. Rather than classifying samples from predefined set gestures, as common existing work learning with mmWave radar, our proposed imager employs...

In this paper, we investigate enhanced super-resolution range estimators with decimeter-level accuracy for multi-antenna and multipath Bluetooth systems. To enhance the traditional MUSIC estimator a two-way frequency-hopping channel model, apply forward-backward averaging bandwidth extrapolation using Burg's algorithm to improve ranging accuracy, which is limited by used quality of estimated sample covariance matrix. For case, compare Summed Antenna Processing Individual methods process...