Hong Kong Applied Science and Technology Research Institute Company, Limited

Honglei Zhang

Yuxian Zhang

Kong Chau Tsang

Jun Xu

Man Wai Kwan

Jiewei Ding

Wing Chau Chan

Yin Yang

Peng Li

Victor Kwan

Eric Tsang

A method for performing high speed mode detection of a carrier frequency offset (CFO) includes receiving a Zadoff-Chu signal at a wireless device, and determining a plurality of correlation peaks based on a correlation of the signal with one or more known Zadoff-Chu sequences. The method includes determining a carrier frequency offset (CFO) associated with the signal based on a phases associated with the plurality of correlation peaks and a coarse CFO estimate. The coarse CFO estimate may be determined based on a squared power ratio of particular pairs of the plurality of correlation peaks and the phases may be used to remove ambiguity associated with the coarse CFO estimate.

Methods for frequency offset estimation with Zadoff-Chu sequences

A methods for performing a cell search in multiple antenna wireless systems using a plurality of spatial filters is disclosed, and includes applying a plurality of spatial filters to a plurality of received signal streams to generate a plurality of filtered signal streams. The plurality of received signal streams correspond to signals received at a plurality of receive antennas from a plurality of signal sources (e.g., neighboring cells). In an aspect, the plurality of spatial filters may be predefined spatial filters and may be weighted using a set of predefined filter weights. In an additional or alternative aspect, the plurality of spatial filters may be adaptive spatial filters and may be weighted using a set of dynamically determined filter weights. The method includes detecting physical network identities based on the plurality of filtered signal streams.

Method for performing a cell search in multiple antenna wireless systems

The present embodiments are directed to systems and methods for detecting random access channel requests, while excluding false random access signals using search windowing and distance-based peak suppression techniques. The present embodiments additionally include further techniques for suppression of fake random access signals, including amplitude thresholds and preamble-based signal exclusion. Beneficially, the present embodiments significantly reduce the false alarm rate, while maintaining a low hardware complexity requirements. In some embodiments, worst-case false alarm rates can be reduced from as much as 20% down to nearly 0.1%.

False alarm reduction with search windowing and peak suppression

This invention discloses a method and an apparatus for reducing false alarm rate in preamble detection due to discontinuities between successive symbols in a received signal. The invention is usable in, e.g., a LTE compliant system. In one embodiment, the apparatus includes a filter for filtering the received signal to yield a filtered signal, and a correlator for correlating the filtered signal with a predetermined preamble. The apparatus further comprises a first multiplier for modifying the received signal before it is filtered, or a second multiplier for modifying the filtered signal before it is correlated, or both. The first multiplier multiplies the received signal with a first time-domain window function configured to substantially smooth discontinuities at symbol boundaries in the received signal. The second multiplier multiplies the filtered signal with a second time-domain window function configured to substantially suppress spikes present in the filtered signal around the symbol boundaries.

Method and apparatus for detecting a preamble in a received signal

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Hong Kong, China

Honglei Zhang