58,648 research outputs found
Design of overcomplete expansions for channel coding
The redundancy afforded by overcomplete expansions have been recently been considered for channel coding. In this paper, we utilise this approach in order to propose a channel coder design to for a correlated additive Gaussian noise channel, of which the noise covariance matrix is assumed to be known. We demonstrate that this approach can lead to a significant reduction of the noise interference by exploiting both the correlation of the channel and the redundancy of the filter banks. Simulation results providing some insight into these mechanisms are provided
Low-complexity high-performance GFSK receiver with carrier frequency offset correction
This paper presents an implementation of a GFSK receiver based on matched filtering of a sequence of K successive bits. This enables improved detection and superior BER performance but requires 2K matched filters of considerable complexity. Exploiting redundancy by performing phase propagation of successive single-bit stages, we propose an efficient receiver implementation. Results presented highlight the benefits of the proposed methd in terms of computational cost and performance compared to standard methods. We also address carrier frequency offset, and suggest a blind algorithm for its elimination. Performance results are exemplarily shown for a Bluetooth system
Detection of cochlear hearing loss applying wavelet packets and support vector machines
The aim of this paper is to evaluate the application of the wavelet packet transform (WP) and support vector machines (SVM) to transient evoked otoacoustic emissions (TEOAE) in order to achieve a detection of frequency-specific hearing loss. We introduce a system to determine detection rates between groups of persons with normal hearing, high frequency hearing loss, and pantonal hearing loss. The validity and use of our approach is verified on a different patient group
A new low-cost discrete bit loading using greedy power allocation
In this paper we consider a low cost bit loading based on the greedy power allocation (GPA). Compared to the standard GPA, which is optimal in terms of maximising the data throughput, three suboptimal schemes are suggested, which perform GPA on subsets of subchannels only. We demonstrate how these schemes can reduce complexity. Two of the proposed algorithms can achieve near optimal performance by including a transfer of residual power between subsets at the expense of a very small extra cost. By simulations, we show that the two near optimal schemes perform best in two separate and distinct SNR regions
Comparison of precoding methods for broadband MIMO systems
In this paper we investigate non-linear precoding solutions for the problem of broadband multiple-input multipleoutput (MIMO) systems. Based on a broadband singular value decomposition (BSVD) we can decouple a broadband MIMO channel into independent dispersive spectrally majorised singleinput single-output (SISO) subchannels. Bit loading is proposed to optimally utilise these SISO subchannels after mitigating their individual inter-symbol-interference (ISI) using Tomlinson- Harashima precoding (THP). This method is benchmarked against recent results of both MMSE linear and THP designed for frequency-selective MIMO channels. Simulation results show that better bit-error-ratio (BER) can be achieved especially for higher throughput targets when compared to the benchmar
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