Abstract: A system and method for performing initial synchronization during wireless sector searches. The system includes a first subsystem for coarse timing alignment including a decimator to reduce computational complexity and a long-lag differential correlator, a second subsystem for jointly estimating RTE and FFO utilizing a short-lag differential correlator, and a third subsystem for jointly detecting IFO and SID utilizing segmental FD MFs. The system and method of the present disclosure accounts for intercell interference, ICI, and multipath fading with assistance from inherent diversity.

Abstract: A system and method for disintegrated channel estimation in wireless networks. The system provides a disintegrated channel estimation technique required to accomplish the spatial diversity supported by cooperative relays. The system includes a filter-and-forward (FF) relaying method with superimposed training sequences for separately estimating the backhaul and the access channels. To reduce inter-relay interference, a generalized filtering technique is provided which multiplexes the superimposed training sequences from different relays to the destination by time-division multiplexing (TDM), frequency-division multiplexing (FDM) and code-division multiplexing (CDM) methods.

Abstract: A system and method for disintegrated channel estimation in wireless networks. The system provides a disintegrated channel estimation technique required to accomplish the spatial diversity supported by cooperative relays. The system includes a filter-and-forward (FF) relaying method with superimposed training sequences for separately estimating the backhaul and the access channels. To reduce inter-relay interference, a generalized filtering technique is provided which multiplexes the superimposed training sequences from different relays to the destination by time-division multiplexing (TDM), frequency-division multiplexing (FDM) and code-division multiplexing (CDM) methods.

Abstract: A system and method for performing initial synchronization during wireless sector searches. The system includes a first subsystem for coarse timing alignment including a decimator to reduce computational complexity and a long-lag differential correlator, a second subsystem for jointly estimating RTE and FFO utilizing a short-lag differential correlator, and a third subsystem for jointly detecting IFO and SID utilizing segmental FD MFs. The system and method of the present disclosure accounts for intercell interference, ICI, and multipath fading with assistance from inherent diversity.

Abstract: The present invention relates to an initial synchronization apparatus assisted by inherent diversity over time-varying frequency-selective fading channels. Based on motivation from statistical derivations, the present invention provides a novel initial synchronization method for estimating timing error and carrier frequency offset (CFO) by embedding matched filters into RAKE fingers to approach modified CramerRao lower bounds (MCRLBs). In addition, the present invention is then built to approach modified CramerRao lower bounds by taking advantage of a maximum ratio combining (MRC) criterion. In practice, the proposed technique can significantly outperform a conventional initial synchronization technique on the timing error and CFO estimations over multipath fading channels.

Abstract: A modified fully digital pseudonoise code tracking loop is proposed in this invention for direct-sequence spread-spectrum communication. By taking advantage of the inherent diversity, a modified code tracking loop is embedded into a RAKE receiver in order to avoid problems caused by unstable locked points of error signals. Such unsteadiness of locked points often occurs with a conventional code tracking loop because the error signals may be randomly biased by multipath fading. Thus, a robust pull-in capability can be provided over a time-variant fading channel where multiple propagation paths are arbitrarily correlated. Furthermore, an effective multipath interference regeneration and cancellation technique is also proposed to improve the error characteristics of the proposed technique. Analytical expressions of the error characteristics and error signals are derived and then confirmed by means of extensive computer simulation results.