Method for generating downlink frame, and method for searching cell

• US 8,320,571 B2
• Filed: 06/19/2009
• Issued: 11/27/2012
• Est. Priority Date: 07/20/2007
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Chang, Kap Seok, KIM, Il Gyu, Park, Hyeong Geun, Ko, Young Jo, YI, Hyo Seok, JEONG, Chan Bok, Kim, Young Hoon, Bang, Seung Chan
• Primary Examiner(s): Shan, April
• Application Number:
  US12/488,272
• Publication Number:
  US 20090252335A1
• Time in Patent Office: 1,257 Days
• Field of Search: 370/350, 370/503, 370/509, 370/208, 370/324, 455/502, 380/287
• US Class Current: 380/287
• CPC Class Codes: H04B 1/70735 Code identification H04B1/7083 takes precedence
• CPC Class Codes: H04B 7/2656 for structure of frame, burst
• CPC Class Codes: H04J 11/0069 Cell search, i.e. determining cell identity [cell-ID] design of multiplexing codes H04J13/00; processing access restriction or access information H04W48/16; discovery of network devices for network data management H04W8/005; sounding signals for channel estimation H04L25/0226; structure of reference signals in multicarrier modulation systems H04L27/2613; frame, time or carrier synchronisation in multicarrier modulation systems H04L27/2655
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/2655 Synchronisation arrangements
• CPC Class Codes: H04L 7/043 Pseudo-noise [PN] codes variable during transmission synchronisation of spread spectrum receivers H04B1/69
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

The present invention relates to a method of generating a downlink frame. The method of generating the downlink frame includes: generating a first short sequence and a second short sequence indicating cell group information; generating a first scrambling sequence and a second scrambling sequence determined by the primary synchronization signal; generating a third scrambling sequence determined by the first short sequence and a fourth scrambling sequence determined by the second short sequence; scrambling the first short sequence with the first scrambling sequence and scrambling the second short sequence with the second scrambling sequence and the third scrambling sequence; scrambling the second short sequence with the first scrambling sequence and scrambling the first short sequence with the second scrambling sequence and the fourth scrambling sequence; and mapping the secondary synchronization signal that includes the first short sequence scrambled with the first scrambling sequence, the second short sequence scrambled with the second scrambling sequence and the third scrambling sequence, the second short sequence scrambled with the first scrambling sequence and the first short sequence scrambled by the second scrambling sequence and the fourth scrambling sequence to a frequency domain.

Claims

1. A method of searching a cell by a mobile station, comprising:

receiving a downlink frame including a primary synchronization signal and two secondary synchronization signals which are different from each other; and

identifying a cell by using the primary synchronization signal and at least one of the two secondary synchronization signal, wherein,

in one secondary synchronization signal of the two secondary synchronization signal, a first short sequence scrambled with a first scrambling sequence and a second short sequence scrambled with a second scrambling sequence and a third scrambling sequence are alternately disposed on a plurality of sub-carriers,

in the other secondary synchronization signal of the two secondary synchronization signal, the second short sequence scrambled with the first scrambling sequence and the first short sequence scrambled with the second scrambling sequence and a fourth scrambling sequence are alternately disposed on a plurality of sub-carriers, and

the first short sequence and the second short sequence indicate cell group information,

the first scrambling sequence and the second scrambling sequence are determined based on the primary synchronization signal, the third scrambling sequence is determined based on the first short sequence, and the fourth scrambling sequence is determined based on the second short sequence.

2. The method of claim 1, wherein the first scrambling sequence and the second scrambling sequence are different from each other.

3. The method of claim 1, wherein the identifying of the cell comprises:

identifying a cell group by using at least one of the two secondary synchronization signals; and

identifying the cell in the cell group by using the primary synchronization signal.

4. The method of claim 1, wherein;

the downlink frame includes a plurality of slots, each slot having a plurality of symbols; and

the primary synchronization signal is located on a last symbol of a slot, and the two secondary synchronization signal is located on a symbol right ahead of the last symbol of the slot.

5. An apparatus for searching a cell by a mobile station, comprising a hardware processor configured to execute:

receiving a downlink frame including a primary synchronization signal and two secondary synchronization signals which are different from each other; and

identifying a cell by using the primary synchronization signal and at least one of the two secondary synchronization signals, wherein, in one secondary synchronization signal of the two secondary synchronization signal, a first short sequence scrambled with a first scrambling sequence and a second short sequence scrambled with a second scrambling sequence and a third scrambling sequence are alternately disposed on a plurality of sub-carriers, and

in the other secondary synchronization signal of the two secondary synchronization signal, the second short sequence scrambled with a first scrambling sequence and the first short sequence scrambled with the second scrambling sequence and a fourth scrambling sequence are alternately disposed on a plurality of sub-carriers, and

the first short sequence and the second short sequence indicate cell group information,

the first scrambling sequence and the second scrambling sequence are determined based on the primary synchronization signal, the third scrambling sequence is determined based on the first short sequence and the fourth scrambling sequence is determined based on the second short sequence.

6. The apparatus of claim 5, wherein the first scrambling sequence and the second scrambling sequence are different from each other.

7. The apparatus of claim 5, wherein:

the downlink frame includes a plurality of slots, each slot having a plurality of symbols; and

the primary synchronization signal is located on a last symbol of a slot, and the two secondary synchronization signal is located on a symbol right ahead of the last symbol of the slot.