In this paper, we present an efficient methodology to designprecoders for distributed detection of unknown high dimensional signals. We consider a wireless sensor network, where several distributed sensors collaborat...
详细信息
ISBN:
(纸本)9780996452762
In this paper, we present an efficient methodology to designprecoders for distributed detection of unknown high dimensional signals. We consider a wireless sensor network, where several distributed sensors collaborate to perform binary hypothesis testing based on observations of an unknown high dimensional signal corrupted by noise. The sensors collect data over both temporal and spatial domains. Due to network resource constraints, each sensor performs a linear compression (through precoding) of the observed high dimensional signal at each time instant and forwards the compressed signal to the fusion center (FC). The FC then employs the generalized likelihood ratio test (GLRT) to make a decision on the presence or absence of the signal. We propose online linear precoding/compression strategies for such sensors that collect data over spatio-temporal domain, so that the detection performance at the FC is maximized under certain network resource constraints. Through the measure of non-centrality parameter and receiver operating characteristics (ROC), we show that our proposed precoder design achieves very good detection performance.
Sensing performance is typically evaluated by classical metrics, such as Cramer-Rao bound and signal-to-clutter-plus-noise ratio. The recent development of the integrated sensing and communication (ISAC) framework mot...
详细信息
ISBN:
(纸本)9781728190549
Sensing performance is typically evaluated by classical metrics, such as Cramer-Rao bound and signal-to-clutter-plus-noise ratio. The recent development of the integrated sensing and communication (ISAC) framework motivated the efforts to unify the metric for sensing and communication, where researchers have proposed to utilize mutual information (MI) to measure the sensing performance with deterministic signals. However, the need to communicate in ISAC systems necessitates the use of random signals for sensing applications and the closed-form evaluation for the sensing mutual information (SMI) with random signals is not yet available in the literature. This paper investigates the SMI and precoder design for sensing applications with random signals. For that purpose, we first derive the closed-form expression for the SMI with random signals by utilizing random matrix theory. The result reveals some interesting physical insights regarding the relation between the SMI with deterministic and random signals. The derived SMI is then utilized to optimize the precoder by leveraging a manifold-based optimization approach. The accuracy of the theoretical analysis and the effectiveness of the proposed precoder design method are validated by simulation results.
Based on convex programming, this paper presents the optimal training signal design for orthogonal frequency-division multiplexing (OFDM) under colored noise. An effective method for OFDM symbol detection with the use...
详细信息
ISBN:
(纸本)9781424402632
Based on convex programming, this paper presents the optimal training signal design for orthogonal frequency-division multiplexing (OFDM) under colored noise. An effective method for OFDM symbol detection with the use of precoding is also described. Both analytical and simulation results show that the proposed design and method can effectively estimate the channel and reliably detect the OFDM symbols. By working in the frequency domain rather than the time domain, the computation complexity of the proposed estimation algorithm is significantly reduced.
This paper proposes a global approach of JPWL (ISO/IEC 15444-11) image transmission over a realistic wireless channel able to ensure the best Quality of Service (QoS). In order to exploit the channel diversity, we con...
详细信息
ISBN:
(纸本)9781457713033
This paper proposes a global approach of JPWL (ISO/IEC 15444-11) image transmission over a realistic wireless channel able to ensure the best Quality of Service (QoS). In order to exploit the channel diversity, we consider a Closed-Loop MIMO-OFDM scheme with different precoder designs. In particular, the high flexibility of QoS precoder allows taking into account the scalability of JPWL jointly with the instantaneous MIMO channel status. This increases the visual quality of received images. The monitoring of the quality is made by a reduced-reference metric (QIP) based on object's saliency and interest point, both linked to human perception. It is performed in association with a robust JPWL decoder to determine the optimal decoding configuration in terms of PSNR. The proposed scheme provides very good results and its performance is shown through a realistic wireless channel.
This paper is motivated by the challenge of high fidelity processing of images using a relatively small set of projection measurements. This is a problem of great interest in many sensing applications, for example whe...
详细信息
ISBN:
(纸本)9781467300469
This paper is motivated by the challenge of high fidelity processing of images using a relatively small set of projection measurements. This is a problem of great interest in many sensing applications, for example where high photodetector counts are precluded by a combination of available power, form factor and expense. The emerging methods of dictionary learning and compressive sensing offer great potential for addressing this challenge. Combining these methods requires that the signals of interest be representable as a sparse combination of elements of some dictionary. This paper develops a method that aligns the discriminative power of such a dictionary with the physical limitations of the imaging system. Alignment is accomplished by designing a projection matrix that exposes and then aligns the modes of the noise with those of the dictionary. The design algorithm is obtained by modifying an algorithm for designing the pre-filter to maximize the rate and reliability of a Multiple Input Multiple Output (MIMO) communications channel. The difference is that in the communications problem a source is being matched to a channel, whereas in the imaging problem a channel, or equivalently the noise covariance, is being matched to a source. Our results shown that using the proposed communications design framework we can reduce reconstruction error between 20%, after only 20 projections of a 28 x 28 image, and 10% after 100 projections. Furthermore, we noticeably see the superior quality of the reconstructed images.
The co-design of radar sensing and communications in dual-functional radar communication systems brings promising advantages for next generation wireless networks by providing gains in terms of the efficient and flexi...
详细信息
ISBN:
(纸本)9798350333077
The co-design of radar sensing and communications in dual-functional radar communication systems brings promising advantages for next generation wireless networks by providing gains in terms of the efficient and flexible use of spectrum, reduced costs, and lower energy consumption than in two separate systems. Besides the challenges associated with the conciliation of the conflicting requirements to perform wireless communication and radar sensing in a real-time cooperation, privacy issues represent a cause of concern as the co-design can let the network prone to active attacks. This paper tackles this issue by evaluating the associated privacy risks with the design of transmit precoders that simultaneously optimise both the radar transmit beampattern and the signal-to-interference-plus-noise at the communication users. Our results show that if a malicious user can infer the transmitted precoder matrix with a certain accuracy, there is a reasonable risk of exposure of the location of the target and privacy breaches.
This paper deals with the design of a hybrid precoder for millimeter-wave MIMO systems. For the sake of concreteness, we consider an analog processing stage composed of a switching network with analog combining. The m...
详细信息
ISBN:
(纸本)9789082797039
This paper deals with the design of a hybrid precoder for millimeter-wave MIMO systems. For the sake of concreteness, we consider an analog processing stage composed of a switching network with analog combining. The main contribution of this work consists on the proposal and evaluation of an optimization procedure based on a smart relaxation. The optimal hybrid precoder under a transmit power constraint is derived, after which, the analog precoding matrix is binarized. After an intuitive reasoning, we note that multiple solutions exist. Nevertheless, the (very) reduced computational complexity of the proposed optimization scheme makes it feasible for realistic implementations. Numerical results are reported to assess the performance of proposed hybrid precoder design.
This paper addresses interference issues in multiuser multiple-input multiple-output (MIMO) downlink heterogeneous networks in which multiple small cells are deployed in macrocell coverage. With the higher priority to...
详细信息
This paper addresses interference issues in multiuser multiple-input multiple-output (MIMO) downlink heterogeneous networks in which multiple small cells are deployed in macrocell coverage. With the higher priority to access the frequency bands, the macro base station (MBS) will exploit eigenmode transmission along with water-filling based power allocation to maximize its data rate. To avoid harmful interference to macro users, we propose structures of the precoders at the small cell BSs (SBSs) as cascades of two precoding matrices. In addition, to mitigate intra-tier inference in small cells, the SBSs exploit the user scheduling schemes for their associated users. We investigate two user scheduling schemes using the minimum interference leakage and maximum signal to noise ratio criteria. The sum rate of the selected users can be further improved by power allocation. We develop an iterative algorithm using difference of convex functions (d.c.) programming to tackle the mathematical challenges of the nonconvex power allocation problem, Numerical simulation results show that the proposed strategy outperforms the conventional methods in terms of the achievable sum rate.
In this paper, we present an efficient methodology to designprecoders for distributed detection of unknown high dimensional signals. We consider a wireless sensor network, where several distributed sensors collaborat...
详细信息
In this paper, we present an efficient methodology to designprecoders for distributed detection of unknown high dimensional signals. We consider a wireless sensor network, where several distributed sensors collaborate to perform binary hypothesis testing based on observations of an unknown high dimensional signal corrupted by noise. The sensors collect data over both temporal and spatial domains. Due to network resource constraints, each sensor performs a linear compression (through precoding) of the observed high dimensional signal at each time instant and forwards the compressed signal to the fusion center (FC). The FC then employs the generalized likelihood ratio test (GLRT) to make a decision on the presence or absence of the signal. We propose online linear precoding/compression strategies for such sensors that collect data over spatio-temporal domain, so that the detection performance at the FC is maximized under certain network resource constraints. Through the measure of non-centrality parameter and receiver operating characteristics (ROC), we show that our proposed precoder design achieves very good detection performance.
暂无评论