Toward Wireless Receivers without Crystals Invited Paper

In new low cost, IOW, bit rate wireless protocols such as ZigbeeTM and BIuetoothTM, there is significant economic motivation to implement transceivers with a completely integrated alternative to quartz crystals. In this paper, we explore a differential detection based method of recovering a direct sequence spread spectrum signal with a receiver that does not have a crystal reference. Despite the additional frequency offset and phase introduced by using an integrated crystaIless reference oscillator, we find that such a receiver is feasible and can perform sufficiently for many applications. Indcr Terms - crystai-less communicstion, differential detection, phase noise.