TDD system random access method and device

A technology of random access and random access preamble, which is applied in multi-frequency code systems, electrical components, wireless communication, etc., can solve the problems of reducing frequency-domain correlation detection performance and achieve the effect of ensuring accuracy

Inactive Publication Date: 2009-05-13
CHINA ACAD OF TELECOMM TECH
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  • Abstract
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Problems solved by technology

[0013] In view of this, the present invention provides a TDD system random access method and device to solve the problem of reducing the performance of frequency-domain correlation detection existing in existing solutions

Method used

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  • TDD system random access method and device
  • TDD system random access method and device
  • TDD system random access method and device

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Embodiment Construction

[0034] The core of the present invention is to obtain the OFDM symbol of the UpPTS as the preamble sequence on the UE side, and then copy the back end of the preamble sequence to the front end as the preamble sequence CP to meet the cyclic characteristics of the preamble sequence so that the Node B can perform frequency domain correlation detection on it . Since the operation of adding CP is performed on the UE side, the back end of the copied preamble sequence is a pure data signal, and no noise will be superimposed. Therefore, compared with the Overlap-and-Add method, it can improve the detection accuracy in the frequency domain and ensure the random access. Work properly.

[0035] In general, the method provided by the invention comprises the following steps:

[0036] 1. On the side of the user equipment UE, construct a random access preamble sequence of N OFDM symbol lengths, copy a signal with a length T at the back end of the preamble sequence to the front end of the pr...

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Abstract

The invention discloses a TDD system random access method comprising establishing a random access leader sequence with N OFDM symbol lengths at a user equipment UE side, copying a signal denoting that a rear end length of the leader sequence is T to a front end of the leader sequence as a cyclic prefix CP; transmitting the CP together with the leader sequence to a base station Node B in a uplink pilot time slot UpPTS by the UE, to request random access. According to the invention, UE side is used for adding the CP to the leader sequence in UpPTS, which will not bring flat noise, and ensures accuracy of correlation detection of a Node B frequency domain, and ensures normal operation of random access. Corresponding to said method, the invention further provides a TDD system random access device.

Description

technical field [0001] The present invention relates to the technical field of mobile communication, in particular to a TDD (Time Division Duplex, Time Division Duplex) system random access method and device. Background technique [0002] In an LTE (Long Time Evolution, long-term evolution) system, uplink random access is divided into asynchronous random access and synchronous random access. Asynchronous random access is a process used by the Node B (base station) to estimate and adjust the UE uplink transmission clock when the UE (User Equipment, user equipment) has not obtained uplink time synchronization or lost synchronization. Node B requests resource allocation. The random access signal is mainly composed of a preamble, and the preamble is used for uplink clock alignment and UE identifier detection. LTE currently includes two asynchronous random access methods. The first access process is: UE sends a preamble sequence for synchronization and resource request at one t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04W74/08H04L27/26
Inventor 王立波孙韶辉索士强潘学明
Owner CHINA ACAD OF TELECOMM TECH
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