Method for setting cyclic shift considering frequency offset

Abstract

A method for establishing a cyclic shift sequence to provide against the frequency offset is disclosed. The method calculates a distance between a channel response position of the sequence and an alias channel response position caused by a frequency offset, calculates the number of cyclic shifts per group according to the calculated distance, and establishes the cyclic shift (CS)-applying interval. This method easily establishes a cyclic shift (CS) interval at a specific location having no overlapping by considering a channel response of a reception (Rx) sequence and an alias location of this reception (Rx) sequence, although a reception (Rx) signal is shifted by a channel delay spreading or a propagation delay irrespective of categories of a domain generating a sequence, so that it can greatly reduce the number of the detection errors and the false alarm rate. And, if a sequence of the cyclic shift (CS) is allocated to a cell having a frequency offset of more than a predetermined level, the present invention can minimize the influence of a frequency offset on a high-mobility cell.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application also claims the benefit of U.S. Provisional Application Ser. No. 60 / 883,754, filed on Jan. 5, 2007, U.S. Provisional Application Ser. No. 60 / 884,398, filed on Jan. 10, 2007, U.S. Provisional Application Ser. No. 60 / 915,096, filed on Apr. 30, 2007 and U.S. Provisional Application Ser. No. 60 / 941,562, filed on Jun. 1, 2007, the contents of which are hereby incorporated by reference herein in their entirety.[0002]This application is a reissue application of U.S. Pat. No. 7,792,212 B2, which issued on Sep. 7, 2010, from U.S. patent application Ser. No. 11 / 969,834, filed on Jan. 4, 2008, which claims the benefit of earlier filing date and right of priority to Korean Patent Application No. 10-2007-0011772, filed on Feb. 5, 2007 and Korean Patent Application No. 10-2007-00102563, filed on Oct. 11, 2007, the contents of which are all hereby incorporated by reference as if fully set forth herein in their entirety.BACKGROUND OF THE...

AI Technical Summary

Benefits of technology

The present invention provides a method for preventing distortion of a sequence caused by frequency offset. This method can easily establish a cyclic shift interval to prevent the sequence deterioration, and can reduce the detection errors and false alarm rate. Additionally, if the cyclic shift sequence is allocated to a cell with frequency offset, it can minimize the impact of frequency offset on high-mobility cells.

Problems solved by technology

However, if the offset occurs in a frequency domain in the same manner as in the case where the CAZAC sequence is transmitted using the OFDM scheme, a performance or false alarm or throughput may be excessively deteriorated.

Specifically, if the cyclic shift (CS) is applied to the CAZAC sequence, the frequency offset or the timing offset excessively occurs, so that it is difficult to discriminate between sequences.

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