Efficient covariance computation by table lookup

US8229044B2 · kind B2 · utility

Assignee

• Telefonaktiebolaget LM Ericsson (Publ) · SE

Inventors

• Andres Reial · Lomma, SE
• Girum Alebachew · Sollentuna, SE
• Elias Jonsson · Malmö, SE

Key dates

• Filing date: Jun 14, 2007
• Grant date: Jul 24, 2012
• Expiry date: Dec 6, 2030

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04B2201/709727
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

The impairment processor described herein uses a look-up table operation to reduce the computational complexity associated with determining an impairment correlation between first and second sample streams for an interference rejection receiver. One exemplary impairment processor iteratively computes multiple partial impairment correlations based on values selected from look-up table(s), and combines the partial impairment correlations to obtain a final impairment correlation between the first and second sample streams. During each iteration, the impairment processor computes a pair of delay offsets corresponding to the respective processing and path delays of the first and second sample streams, computes an index value as a function of a difference between the pair of delay offsets, selects a pre-computed value from the look-up table based on the index value, determines a pulse correlation estimate based on the selected pre-computed value, and determines the partial impairment correlation for that iteration based on the pulse correlation estimate.