As a part of the PicoRadio project to build a ubiquitous ad-hoc wireless sensor node network, the physical layer has to provide a reliable point-to-point radio link under very tight power constraints. The analog transceiver building blocks make up a large percentage of the overall power budget. In order to minimize the amount of energy needed to convey one bit of information, new strategies have to be employed which take into account the power consumption not only in a communication theoretic sense in the form of energy transmitted over the channel, but also the energy needed to meet performance requirements of the analog and digital building blocks in the receiver chain. Following this approach, the PicoRadio RF group is implementing a transceiver utilizing the least number of analog components possible together with promising new technologies like RF-MEMS . To evaluate the performance, my research focuses on modeling the radio link, including these blocks. I developed a behavioral simulation framework for a point-to-point link and further abstracted the design into an analytical model. From this model, we can derive performance specifications for the blocks under development and can use them in the design process.