United States Patent 8,014,361
Ozluturk September 6, 2011
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Random access channel for OFDM-MIMO system
Abstract
In orthogonal frequency division multiplexing (OFDM) multiple-input multiple-output (MIMO) systems, a wireless transmit/receive unit (WTRU) selects a random access channel (RACH) and a phase for a constant amplitude zero auto correlation (CAZAC) sequence for RACH transmission. The WTRU then transmits a RACH transmission to a Node B via the selected RACH. Once the RACH transmission is detected, the Node B sends an acknowledgement (ACK) to the WTRU over an ACK channel. The Node B may transmit the ACK on a shared channel. The WTRU may ramp up transmit power while the RACH transmission is transmitted, or steps up transmit power of a subsequent RACH transmission. The RACH transmission and data transmission may be either time multiplexed or frequency multiplexed. A plurality of RACHs may be defined and one of the defined RACHs may be selected randomly or based on predetermined criteria.
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Inventors: Ozluturk; Fatih M. (Port Washington, NY)
Assignee: InterDigital Technology Corporation (Wilmington, DE)
Appl. No.: 11/746,363
Filed: May 9, 2007
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Related U.S. Patent Documents
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Application Number Filing Date Patent Number Issue Date
60798970 May., 2006
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Current U.S. Class: 370/335 ; 370/208; 370/235; 370/329; 370/330; 370/343; 370/344; 370/395.21; 370/436; 370/480; 455/435.1; 455/45; 455/450; 455/452.1; 455/452.2; 455/456.2; 455/456.5; 455/502; 455/515; 455/550.1; 455/561; 455/60; 455/63.1
Current International Class: H04B 7/216 (20060101)
Field of Search: 455/411,410,435.1,414.1,502,515,63.1,60,45,450,452.1,452.2,456.2,456.5,522,500,464,550.1,561,259,249 713/183,171,168,155,160,185 370/64,480,335,344,235,436,329,330,395.21,208,342
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