A cross-correlation sub-sampling receiver for low power applications in a low SINR environment

Wireless sensor networks have recently emerged in a wide range of applications. Many attributes are essential for such networks such as: low cost, small form-factor, limited peak power consumption and the ability to operate in harsh interference scenarios. Most of these networks do not require high data-rates to operate. In this respect, sub-sampling receivers have shown promising results but suffer from noise folding and interference aliasing. In this paper, a sub-sampling receiver in combination with cross-correlation is used to enhance sensitivity and interference robustness while maintaining the sub-sampling advantages. An architecture which uses two different sampling frequencies is proposed. It shows ∼2dB SNR improvement compared to traditional architectures due to cross-correlation and an additional ∼2dB for each doubling of integrations. For a BER of 10– 3 , the required SIR is reduced with 4.5dB, 11.5dB and 14.5dB after using cross-correlation with the same, half and quarter data-rate used respectively. These improvements allow for a lower-power and lower-cost implementation.