| Advances in the information age have allowed people to communicate with each other ubiquitously. The main feature for any-time-any-where transfer of information is mobility, with wireless devices being the essential ingredients of mobile communications. To help proliferate these devices, industrial standards were developed. One of the digital wireless standards is Code Division Multiple Access (CDMA). CDMA is based on the direct sequence spread spectrum (DSSS) technology that existed since the mid-1900's. Its popularity is due, at least in part, to its inherent frequency diversity, easy frequency management, and other benefits which make wireless communications commercially acceptable.;Some of the important parameters for wireless devices are power efficiency and through-put. Optimizing power provides longer battery life in wireless gadgets and increasing through-put permit operation of wideband applications. One of the operations that must be optimized in DSSS systems is called Pseudo-Noise (PN) acquisition. PN acquisition introduces overhead for DSSS communications which leads to degradation of through-put. In addition, circuit complexity and power dissipation for PN acquisition can also be considerable. Due to these challenges, there have been efforts to research a suitable architecture and implementation for efficient PN acquisition. Past research, however, has not answered the energy dissipation question in PN acquisition.;This work answers the question of energy consumption amongst standard architectures using serial correlators and matched filters. One architecture, called the hybrid, is found to have fast PN acquisition time and low energy dissipation. The hybrid two-dwell architecture is based on autocorrelation techniques using either serial correlators or matched filters. Unlike previous works, the PN acquisition process is analyzed here without gaussian approximations. A testbed is setup for measurements and confirmation of analysis. The hybrid architecture is found to have up to 10 times faster PN acquisition while dissipating half as much energy as some traditional designs. |
