This paper considers the (NP-)hard problem of joint multicast beamforming and antenna selection. Prior work has focused on using Semi-Definite relaxation (SDR) techniques in an attempt to obtain a high quality sub-optimal solution. However, SDR suffers from the drawback of having high computational complexity, as SDR lifts the problem to higher dimensional space, effectively squaring the number...

We consider supervised dimension reduction (SDR) for problems with discrete variables. Existing methods are computationally expensive, and often do not take the local structure of data into consideration when searching for a low-dimensional space. In this paper, we propose a novel framework for SDR which is (1) general and flexible so that it can be easily adapted to various unsupervised topic ...

We describe a multicore Software-Defined Radio (SDR) architecture for Global Navigation Satellite System (GNSS) receiver implementation. A GNSS receiver picks up very low power signals from multiple satellites and then uses dedicated processing to demodulate and measure the exact timing of these signals from which the user’s position, velocity, and time (PVT) can be estimated. Three GNSS SDR ar...

Factor models are widely used in summarizing large datasets with few underlying latent factors and in building time series forecasting models for economic variables. In these models, the reduction of the predictors and the modeling and forecasting of the response y are carried out in two separate and independent phases. We introduce a potentially more attractive alternative, Sufficient Dimensio...

To increase the productivity in various sectors, foundation can be made based on mobile communication solutions to different problems. SDR is the preferred technology to stitch together advanced services for ubiquitous global mobile connectivity. We have investigated in the present study the Sigma Delta ADC, one important component of SDR. Improvement in Dynamic Range including the SFDR with a ...

The ability to support multiple channels of different communication standards, in the available bandwidth, is of importance in modern software defined radio (SDR) receivers. An SDR receiver typically employs a channelizer to extract multiple narrowband channels from the received wideband signal using digital filter banks. Since the filter bank channelizer is placed immediately after the analog-...

Sediment delivery ratio (SDR) is traditionally defined as the fraction of upland gross erosion that is transported out of a defined area, e.g., a plot or catchment. It is, effectively, an index of sediment transport efficiency. Previously, it is treated as an empirically-lumped parameter used as a mechanism for compensating for sediment deposition within a catchment area. In this paper, we prop...

Software defined radio (SDR) is emerging as a powerful platform for future generation cellular systems, due to its capability to operate conforming to multiple mobile radio standards. Channelizer in an SDR operates at the highest sampling rate and hence a low complexity design is needed for the most computationally intensive part of the SDR receiver. The channel filters in the channelizer extra...

Clearly (1) has an SDR provided that |Ai| > i for all i = 1, · · · , n, in particular an SDR of (1) exists if |A1| = · · · = |An| > n or 0 < |A1| < · · · < |An|. Let G be an additive abelian group and A1, · · · , An its subsets. We associate any SDR (2) of (1) with the sum ∑n i=1 ai and set (4) S({Ai}i=1) = S(A1, · · · , An) = {a1 + · · ·+ an : {ai}i=1 forms an SDR of {Ai}i=1} . Of course, S(A1...

In this paper we describe the LIMSI Spoken Document Retrieval system used in the TREC-9 evaluation. This system combines an adapted version of the LIMSI 1999 Hub-4E transcription system for speech recognition with text-based IR methods. Compared with the LIMSI TREC-8 system, this year’s system is able to index the audio data without knowledge of the story boundaries using a double windowing app...