Frederic Guilloud

• Institut Mines-Télécom

Satellites receiving Automatic Identification System (AIS) packets in dense areas are particularly prone to AIS channel overload due to the extensive number of vessels. Thus a failure of detection might be caused by the collisions among AIS messages. To improve the detection capability, we propose to exploit the presence of the cyclic redundancy ch...

The conventional non-coherent differential detection of continuous phase modulations (CPM) is quite robust to channel impairments such as phase and Doppler shifts. Its implementation is on top of that simple. It consists in multiplying the received baseband signal by its conjugate version delayed by one symbol period. However it suffers from a sign...

The objective of this paper is to minimize the energy consumption of a quantized Min-Sum LDPC decoder, by considering aggressive voltage downscaling of the decoder circuit. Since low power supply may introduce faults in the memories used by the decoder architecture, this paper proposes to optimize the energy consumption of the faulty Min-Sum decode...

Orthogonal Frequency Division Multiplexing (OFDM) is one of the key modulations for current and novel broadband communications standards. For example, Multi-band Orthogonal Frequency Division Multiplexing (MB-OFDM) is an excellent choice for the ECMA-368 Ultra Wideband (UWB) wireless communication standard. Nevertheless, the high Peak to Average Po...

We consider the transmissions of successive short packets. Each of them combines information to be transmitted (codeword) with information for synchronizing the frame (syncword). For short packets, the cost of including syncwords is no longer negligible and its design requires careful optimization. In particular, a trade-off arises depending on the...

This paper addresses finite-alphabet block-sparse signal recovery by considering support detection and data estimation separately. To this aim, we propose a maximum a posteriori (MAP) support detection criterion that takes into account the finite alphabet of the signal as a constraint. We then incorporate the MAP criterion in a compressed sensing d...

We consider the transmission of successive packets where each packet consists of a frame synchronization word (SW), followed by coded symbols. For short packets the header cost is no longer negligible and SW design requires careful optimization. In particular, a trade-off arises depending on the way the total transmit power is split among the SW an...

In this paper, we derive an efficient iterative algorithm for the recovery of block-sparse signals given the finite data alphabet and the non-zero block probability. The non-zero block number is supposed to be far smaller than the total block number (block-sparse). The key principle is the separation of the unknown signal vector into an unknown sup...

Considering a fixed frame length, a trade-off exists between improving the performance of frame synchronization (FS) versus improving the performance of information throughput. In this paper, we consider the case of continuous transmission over AWGN channels where the synchronization sequence is superimposed to the data symbols, as opposed to being...

Intersymbol interference (ISI) cancellation over frequency-selective underwater acoustic channel (UAC) is usually performed efficiently using iterative equalization. To this aim, an interleaver is required between the error correction scheme and the modulation scheme, and the longer the interleaver block length the better the performance. However,...

We develop a robust multiuser detector for a Frequency Division Multiplexing (FDM) system where each user employs a binary continuous phase modulation (CPM) generated through a low-cost transmitter, thus characterized by a significant modulation index uncertainty, and sent over a channel affected by phase noise. In this FDM system the spectral effi...

A method is provided for transmitting a digital signal between at least two transmitters and at least one receiver, using a concatenation of at least two codes. The method includes a first encoding step, in the transmitters, which outputs at least two first code words; a first transmission step of the first code words, via at least two distinct tra...

Most source coding standards (voice, audio, image and video) use Variable-Length Codes (VLCs) for compression. However, the VLC decoder is very sensitive to transmission errors in the compressed bit-stream. Previous contributions, using a trellis description of the VLC codewords to perform soft decoding, have been proposed. Significant improvements...

A wireless communication system constructed by a MIMO antenna system and transmitting information from a transmitter having Nt number of transmitting antennas to a receiver 3 having Nr number of receiving antennas. The receiver 3 of this wireless communication system 1 linking the inputs and outputs between a demodulating unit 32 demodulating the i...

A parity check matrix construction method for constructing a non-binary parity check matrix defining a non-binary LDPC code. In particular, a parity check matrix construction method for setting codewords able to stably give a superior decoding performance is provided. For this reason, the non-binary non-zero elements are selected so that the determ...

Non-binary LDPC codes have interesting performances, especially for short to moderate blocklengths. The decoding schedule of these codes decoding, similarly to the binary case, has an important impact on the decoder's behaviour and should be carefully designed. This paper studies and optimizes the layered scheduling of non-binary LDPC codes followi...

To reduce the peak-to-average power ratio (PAPR) of an orthogonal frequency division multiplexing (OFDM) modulation scheme, one class of methods is to generate several OFDM symbols (candidates) carrying the same information and to select for transmission the one having the lowest PAPR. We derive a theoretical amplitude probability density function...

A probabilistic PAPR reduction method using binary masks is proposed for OFDM systems. The binary masks are used to generate multiple signal candidates containing the same information. The candidate with the lowest PAPR is selected for transmission. In the presence of a non-linear amplifier (soft limiter), as the number of candidates increases, the...

We consider the multiple candidate OFDM systems as a class of probabilistic method to reduce the peak to average power ratio (PAPR) of OFDM symbols. The candidate having the lowest PAPR is selected for transmission. For that, many IFFTs have to be processed to measure the PAPR of each candidate, which can be too complex for handheld devices. We pro...

It is usually assumed that N samples of the time domain orthogonal frequency division multiplexing (OFDM) symbols have an identical Gaussian probability distribution (PD) in the real and imaginary parts. In this article, we analyze the exact PD of M-QAM/OFDM symbols with N subcarriers. We show the general expression of the characteristic function o...

Selected mapping (SLM) is considered as a practical probabilistic PAPR reduction method for OFDM systems. A problem of this technique is its high computational complexity due to multiple inverse Fourier transform. We suggest a decimation in frequency IFFT scheme together with an interleaver butterfly ensemble to generate multiple candidates. Orthog...

While probabilistic OFDM-PAPR reduction techniques show a good PAPR reduction performance as a distortionless technique, three important problems should be taken into consideration: low complexity design to generate multiple candidates, protection of side information, and effective PAPR reduction regardless of the channel coding model. We present l...

We present partial blind selected mapping method (P-BSLM) as a probabilistic OFDM-PAPR reduction method. The P-BSLM method generates more candidates than the classical SLM (C-SLM) method while using the same number of IFFT computations. Moreover, common stage computation in an IFFT process can reduce the computational complexity. More candidates in...

This paper proposes a joint source channel coding scheme for robust real time transmission of H.264/AVC -coded -video over noisy channels and under bandwidth limitations. A new method of rate adaptation to the -allowed -maximum channel transmission rate which does not assume source rate control in the source coder has been -proposed. This keeps sys...

In this paper we propose the Arranged List of the Most a priori Likely Tests (ALMLT) algorithm, which is an efficient algorithm for reliability-based soft-decision decoding of long linear block codes. Based on order statistics, we define the mean bit reliabilities and use them to estimate the a priori weight of an error pattern. Each error pattern...

Through a rapid survey of the architecture of low-density parity-check (LDPC) decoders, this paper proposes a general framework to describe and compare the LDPC decoder architectures. A set of parameters makes it possible to classify the scheduling of iterative decoders, memory organization, and type of check-node processors and variable-node proce...

In this paper we study the sensibility of the recently proposed Arranged List of the Most a priori Likely Tests (ALMLT) algorithm to the real signal to noise ratio (SNR) of the received bits for a list of tests generated off-line at a given SNR. The ALMLT algorithm is an efficient method for reliability-based soft-decision decoding of long linear b...

This paper presents a novel construction method for parity-check matrices of non-binary LDPC codes which selects nearly optimum non-zero elements in the parity-check matrices. The proposed method can improve the codeweight distribution of non-binary LDPC codes of column weight 2. The decoding performance of the non-binary LDPC codes using the parit...

We propose to use non-binary low density parity check (LDPC) codes for small packet transmissions in vehicle communications. Non-binary LDPC codes which are defined by a parity check matrix over non-binary Galois field GF(q) can achieve performance very close to the Shannon limit even if they are applied to small block length. By using computer sim...

et par sa modularité, différents algorithmes de calcul (dits processeur de noeuds) et de séquencement peuvent être testés. Enfin, notre travail nous a permis de dégager un cadre formel d'analyse et de synthèse des architectures de décodeurs LDPC. Ce cadre englobe à la fois les chemins de données (parallélisme, architecture des processeurs de noeuds...

- Le décodage optimal des codes LDPC met en oeuvre un algorithme itératif qui propage les informations extrinsèques et les informations a priori dans le graphe bipartite reliant les variables aux équations de parité. Nous proposons dans cet article tout d'abord une simplification du calcul de parité, qui facilite le décodage et son implementation a...

In this paper, the decoding of low- density parity-check (LDPC) codes is considered. A new algorithm, named Min algorithm, for updat- ing extrinsic information is proposed. The Min algorithm oers dierent trade-o performance ver- sus complexity between the belief propagation (BP) algorithm (optimal but complex) and the universal most powerful (UMP)...

We investigate the real-time probing of nonequilibrium electron transfers in aqueous solutions of disulfide molecules. Our attention is focused on the elementary steps of an IR electron transfer from a charged donor (chloride ion) to a biomolecular acceptor (cystamine dihydrochloride: RSSR, 2HCl, R = (CH2)2 NH2). Following a femtosecond UV excitati...

The purpose of this paper is to calculate the bit error rate (BER) of a multiband non-coherent on-off keying (OOK) demodulation. The results fit perfectly the simulations of the system. It allows us to study the influence of the filter and the decimation factor on the modulation performance. It is also possible to optimize the system by means of ot...

The primary steps of a one-electron reduction of a disulfide molecule (cystamine) by the infrared p-like state of an excited hydrated electron have been investigated by femtosecond laser spectroscopy. The initial electron photodetachment from chloride ion or phenothiazine is triggered by a two-photon ultraviolet excitation. In homogeneous aqueous c...