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US 8,427,971 B2Granted
Enhancement of LTE random access procedure
AssigneeLG Electronics Inc.
InventorsPatrick Fischer, Remi Feuillette, Dragan Vujcic
Life of this patent
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Abstract
A method and apparatus for enhancement of the random access procedure of a Long-Term Evolution (LTE) system are provided. Enhancements include modeling one cycle in the random access procedure since only one counter is necessary and controlling the delay prior to the preamble transmission in order to reduce conflicts by multiple mobile terminals using the random access channel.
Claims22
A method of performing a random access procedure in a wireless communication system, the method comprising:
- receiving random access information through a broadcast channel, the random access information comprising at least random access signature information, a power ramping parameter or an access slot configuration parameter;
- initiating a random access procedure according to a cause parameter, the cause parameter corresponding to a condition requiring a new random access before each preamble transmission;
- selecting a first signature for use in the preamble, the first signature based on the random access signature information;
- determining a first access slot for transmission of the first signature on a random access channel, the first access slot based on the access slot configuration parameter;
- determining transmission power for transmission of the first signature;
- transmitting the preamble comprising the first signature using the determined first access slot;
- selecting a second signature which is different from the first signature for re-transmission of the preamble based on a system frame number (SFN) when the transmission of the preamble comprising the first signature is not successful;
- and
- determining a second access slot for the re-transmission of the second signature by applying a cyclic shift to the first access slot based on the SFN when the transmission of the preamble comprising the first signature is not successful, the second access slot not overlapping with the first access slot.
6 more elements
A mobile terminal for performing a random access procedure in a wireless communication system, the mobile terminal comprising:
- a transmitting unit transmitting signals;
- a receiving unit receiving random access information through a broadcast channel, the random access information comprising at least random access signature information, a power ramping parameter or an access slot configuration parameter;
- a display unit displaying information;
- an input unit receiving inputs from a user;
- and
- a processing unit initiating a random access procedure according to a cause parameter, selecting a first signature for use in the preamble, determining a first access slot for transmission of the first signature on a random access channel, determining transmission power for transmission of the first signature, controlling the transmitting unit to transmit the preamble comprising the first signature using the first access slot, selecting a second signature which is different from the first signature for re-transmission of the preamble based on a system frame number (SFN) when the transmission of the preamble comprising the first signature is not successful, and determining a second access slot for the re-transmission of the second signature by applying a cyclic shift to the first access slot based on the SFN when the transmission of the preamble comprising the first signature is not successful, the second access slot not overlapping with the first access slot,
- wherein the cause parameter corresponds to a condition requiring a new random access before each preamble transmission, the first signature is based on the random access signature information, and the first access slot is based on the access slot configuration parameter.
4 more elements
Dependencies are inferred from the claim text.