The presented work considers a CDMA-based Wireless Body Area Network (WBAN) where multiple biosensors communicate simultaneously to a central node in an asynchronous fashion. The asynchronous nature of the WBAN introduces Multiple Access Interference (MAI). To combat this problem, presented is a methodology that uses a set of cyclically orthogonal spreading codes extracted from the Walsh-Hadamard matrix. When using the Cyclic Orthogonal Walsh-Hadamard Codes (COWHC) as spreading codes in the CDMA-based WBAN, the cyclic orthogonality property helps mitigate MAI amongst the on-body sensors. Presented is an ideal communication system that is most effective at mitigating MAI in proactive WBANs. The work illustrates the system optimality and effectiveness at mitigating MAI by studying the sensitivity to packet-loss through simulating the link Bit Error Rate (BER) performance. It is shown that the proposed design with COWHC, a Rayleigh flat-fading channel, BPSK modulation and a conventional receiver produce optimum MAI mitigation.

The presented work considers a CDMA-based Wireless Body Area Network (WBAN) where multiple biosensors communicate simultaneously to a central node in an asynchronous fashion. The asynchronous nature of the WBAN introduces Multiple Access Interference (MAI). To combat this problem, presented is a methodology that uses a set of cyclically orthogonal spreading codes extracted from the Walsh-Hadamard matrix. When using the Cyclic Orthogonal Walsh-Hadamard Codes (COWHC) as spreading codes in the CDMA-based WBAN, the cyclic orthogonality property helps mitigate MAI amongst the on-body sensors. Presented is an ideal communication system that is most effective at mitigating MAI in proactive WBANs. The work illustrates the system optimality and effectiveness at mitigating MAI by studying the sensitivity to packet-loss through simulating the link Bit Error Rate (BER) performance. It is shown that the proposed design with COWHC, a Rayleigh flat-fading channel, BPSK modulation and a conventional receiver produce optimum MAI mitigation.

Dans le cadre d'une interdisciplinarité, cette thèse analyse les réseaux médico-sociaux et mesure la performance de la communication au sein même de ces réseaux.D'après les préceptes de l'épistémologie constructiviste, l'observation de la réalité scientifique repose non pas uniquement sur l'observance objective du réel mais aussi sur la connaissance du réel de par sa propre expérience. Nous avons donc mené une analyse à travers une démarche d'enquête longitudinale et prospective par questionnaires, réalisée sur 161 patientes atteintes de cancer du sein : en parallèle, des entretiens qualitatifs ont été réalisés auprès de 40 représentants du personnel soignants.Nous cherchons tout d'abord à mettre en évidence la distanciation communicationnelle entre le personnel soignants et les soignés en mettant l'accent sur l'analyse du traitement de l'information dans un but d'aider les patientes à modifier leurs schémas dysfonctionnels pour aboutir à des schémas fonctionnels par l'intermédiaire des questionnaires.Les résultats d'analyse des enquêtes quantitatives et qualitatives réalisées pendant 14 mois, nous ont permis de mettre en place une approche systémique au sein d'un établissement de santé dans le cadre d'un projet de portail communicationnel entre soignants et soignés. Les analyses prospectives ont en effet révélé l'importance des théories systémiques qui s'appuient elles-mêmes sur les théories de la communication et se fondent sur un modèle de causalité circulaire pour s'intéresser au système au sein duquel l'individu interagit. / In the context of an interdisciplinarity, this thesis analyses the socio-medical networks and the performance of communication within these networks. Following the precepts of constructivist epistemology, the observation of the scientific reality is not only based on the objective observance of the reality, but also on the experience-guided knowledge of the reality. We have thus realized an analysis throughout a longitudinal and prospective survey approach by questionnaires, within 161 breast cancer patients. In parallel, qualitative interviews were taken with 40 representatives of the health care staff.First of all, we want to highlight the communicational detachment between the health care providers and the patients by accentuating on the analysis of information handling, with the objective to help the patients to modify their dysfunctional schemas to functional schemas, via questionnaires.The analysis results from the quantitative and qualitative surveys realized during 14 months permitted us to set up a systemic approach within the health care establishment in the form of a project for a communicational portal between health care providers and patients. In fact, the prospective analyses revealed the importance of systemic theories which are themselves based on communication theories and circular causality models to be interested in the system in which the patient interacts.