Blind detection techniques for IEEE 802.15.4a communication system

This paper considers the ultra wideband multi-user communication system of the IEEE 802.15.4a-2007 standard. We propose a receiver scheme based on sampling at chip rate followed by a filter matched to the so-called effective user code. Two blind estimators for the effective code are proposed. The first one is a full rank estimator which is efficient and simple to implement and does not involve complex matrix operations as usually required in other blind estimators. The second estimator uses a reduced rank processing stage, which is based in two steps: interpolation and decimation. These steps are jointly designed to optimize the output signal to noise ratio (SNR) of the observed reduced rank signal. The proposed reduced rank processing is incorporated to the blind estimator to produce a reduced rank blind estimator. Numerical results show the validity of the proposed receiver and estimators in multiuser transmission environments.