Recent accomplishments in link-level and radio technologies have significantly improved the performance of wireless links. Wireless mobile ad hoc networks, however, typically only take limited advantage of these enhancements. In this research, the medium access control protocol and ad hoc routing protocol are extended to take advantage of radios offering multi-user interference cancellation and direct-sequence spread-spectrum functionality, by encouraging multiple simultaneous connections and adaptively changing communication parameters on a per-packet basis. Through its environment characterization techniques, the adaptive direct sequence spread spectrum MAC protocol for non-broadcast multiple access networks (ADIM-NB) improves several aspects of the wireless mobile ad hoc network performance, including throughput, delay, stability, and power consumption, through its use of spread-spectrum multiple access and four different adaptive algorithms. The four adaptive algorithms change processing gain, forward error correction coding rate, transmit power, and number of simultaneous connections. In addition, the ad hoc routing protocol is extended with the clustering algorithm for mobile ad hoc network (CAMEN). With ADIM-NB in mind, CAMEN discourages the use of broadcast messages, supplements ADIM-NB's functionality at the network level, and improves the network scalability by aggregating nodes into clusters. Both protocols are intended to lead to more powerful and flexible communication capabilities for wireless nodes. Simulation models have been developed and simulated to verify the performance improvements of both protocols at the network-level as well as provide a means to perform trade-off analysis. Results indicate that the network capacity is increased between 50% in a moderately loaded network to 100% in a heavily loaded network over a non-adaptive MAC protocol. The delay also improve significantly in most scenarios of interest. / Ph. D.

Orientador: Celso de Almeida / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-24T01:46:06Z (GMT). No. of bitstreams: 1 Mello_RodolphoContiGianiniFerreira_M.pdf: 1434278 bytes, checksum: c9d50dad0686c63ee7429ff495370ace (MD5) Previous issue date: 2013 / Resumo: Os fatores responsáveis pela vazão de dados em uma rede celular são o número de usuários alocados em uma célula e a taxa de dados de cada usuário. Desta forma, para alcançar melhores resultados em termos de vazão de dados, deve-se utilizar de técnicas que trabalhem com foco no produto destes dois parâmetros. Este trabalho consiste em uma análise comparativa entre diferentes sistemas CDMA sob a ótica da vazão de dados, tendo como foco sequências de espalhamento do tipo aleatórias e também de Walsh e detecção com filtro casado e com o detector multiusuário descorrelacionador (MUD-D - Multiuser Detector Decorrelator), além de considerar a presença de interferência interna e externa no sistema. O método utilizado para a análise e comparação consiste na modelagem matemática do enlace reverso de um sistema celular DS-CDMA em canal AWGN com controle perfeito de potência e com alguns parâmetros fixos, tais como, a taxa máxima de erro de bit ( ), a taxa mínima de dados por usuário (10 kbps, referente ao serviço de voz) e a potência máxima de transmissão de 0,5W por estação móvel. Este trabalho apresenta também uma análise comparativa entre um sistema DS-CDMA com filtro casado e outro com o detector MUD-D na presença de interferência externa. A análise comparativa do detector MUD-D com o filtro casado em ambiente com interferência externa e toda a análise da vazão de dados do sistema são contribuições do autor / Abstract: The factors responsible for the data throughput in a cellular network are the number of users allocated in a cell and the users' data rate. This way, to reach better results in terms of data throughput, one must use techniques that act with focus on the product of those two parameters. This work consists in a comparative analysis among different CDMA systems from the perspective of the data throughput, focusing on random and Walsh spreading sequences and detection method with matched filter and with the multi-user detector decorrelator (MUD-D), besides considering the presence of internal and external interference in the system. The analysis and comparison methods consist in the CDMA cellular system uplink mathematical modelling in an AWGN channel considering a perfect power control and some fixed parameters such as the maximum bit error rate ( ), minimum data rate per user (10 kbps, referring to the voice service) and maximum transmitting power of 0.5 W per mobile station. This work also presents a comparative analysis between a DS-CDMA system with matched filter and another with the MUD-D detector in the presence of external interference. The MUD-D and matched filter comparative analysis in a scenario with external interference and the whole system's data throughput analysis are the author's contribution / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica