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Preamble signal transmission method and apparatus

A technology of preamble signals and devices, applied in the field of communication, can solve the problems of high overhead, high implementation complexity and power consumption, and signals cannot be received normally, and coarse synchronization is lost.

Active Publication Date: 2016-06-01
DATANG MOBILE COMM EQUIP CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In case one, it is found that the signal is received well, and the UE can achieve synchronization well at this time; in case two, since the signal is found to be interfered intermittently by WiFi, the problem of coarse frequency offset and coarse symbol timing maintenance is not big, such as fractional frequency offset The timing synchronization of fine and fine symbols may be lost; in case three, the deployment of 802.11ac can occupy 80M or 160M bandwidth in the unlicensed frequency band, and the competition in hotspot areas is fierce, and the detection signal is sparse and easy to collide with WiFi signals, which may cause After a long period of time, it was found that the signal could not be received normally and the coarse synchronization was lost.
In addition to the scenario where the discovery signal may fail in case 3, there are a large number of optional frequency points in the unlicensed frequency band. For the UE, it needs to receive the discovery signal at all frequency points. The implementation complexity and power consumption are higher than the smallcell case, and the discovery The signal occupies multiple subframes and the overhead is high, so from a technical point of view, it is also necessary to consider the discovery of signal failure or possible alternatives to the discovery signal
[0009] To sum up, how the LTE system works on the unlicensed spectrum has not given a clear solution

Method used

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  • Preamble signal transmission method and apparatus
  • Preamble signal transmission method and apparatus
  • Preamble signal transmission method and apparatus

Examples

Experimental program
Comparison scheme
Effect test

Embodiment approach 1

[0120] Embodiment 1, the time domain structure of the three parts of the preamble signal determined by the base station to be sent to the UE is as follows: image 3 shown, and complies with the following principles:

[0121] If preambleII exists, it consists of one OFDM symbol from the time domain. The OFDM symbol consists of a cyclic prefix (CP) and two periodic sequences C. The periodic sequence C may be generated by a frequency-domain pseudo-noise (Pseudo-noiseSequence, PN) sequence or a zadoff-chu sequence or other sequences with good correlation characteristics.

[0122] preambleI is represented by a sequence A, its length is variable, and the number of samples is |A|, which can be any sequence or a part of preambleII. Preferably, the preambleII sequence [CPCC] is taken according to the length |A| of preambleI The preceding |A| or the following |A| samples are used as preambleI. If |A|=0, the preambleI part does not exist.

[0123] PreambleIII is represented by sequence...

Embodiment 1

[0134] Assume that when the base station randomly accesses the channel, it is located at the Mth OFDM symbol and the Nth sample point of a certain subframe. When using a conventional CP, M is a positive integer less than or equal to 14, N is a positive integer, and its size Depends on sample rate.

[0135] If M=1, N=1, the access time of the base station is at the start position of a certain subframe. If the base station is ready to send data at this time, the placeholder may not be sent, and the lengths of preambleI, preambleII, and preambleIII are all set is 0;

[0136] If 13>M>1, N>1, that is, the random access time of the base station is not the starting position of a certain OFDM symbol in the subframe, and at least two complete OFDM symbols are included from the accessing time to the starting position of the next complete subframe , the base station can send preambleI on the Nth sample point of the Mth OFDM symbol to the last sample point of the OFDM symbol, send preamb...

Embodiment approach 2

[0141] The preamble signal is still composed of three parts, but different from the above scheme one, the preambleII occupying one OFDM symbol in scheme one is replaced by the preambleII occupying two OFDM symbols. The preambleII composition form of two OFDM symbols is [CP1C1CP1C1] or [CP2C1C1]. The former uses the traditional cyclic prefix, that is, the first cyclic prefix CP1, [CP1C1] to form an OFDM symbol, and the latter two OFDM symbols share a cyclic prefix, that is, the second cyclic prefix CP2, where the length of CP1 is half the length of CP2.

[0142] If preambleI exists, it is represented by sequence A, the number of samples is |A|, its length is less than preambleII, that is, less than two OFDM symbol lengths, and it can be any sequence. Preferably, preambleII is taken according to the length of preambleI |A| The front |A| or the last |A| sample points of the sequence are used as preambleI. If |A|=0, the preambleI part does not exist.

[0143] PreambleIII is repre...

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Abstract

The invention discloses a preamble signal transmission method and apparatus for achieving the occupation of an LTE system on an unlicensed frequency spectrum through a preamble signal and further achieving the work of the LTE system on the unlicensed frequency spectrum. The preamble signal transmission method provided by the invention comprises that a base station determines a preamble signal required to be transmitted when a channel is accessed onto the unlicensed frequency spectrum randomly; and the base station transmits the preamble signal to user equipment (UE) on a full bandwidth or partial bandwidth accessed with the channel on the unlicensed frequency spectrum.

Description

technical field [0001] The present invention relates to the field of communication technologies, in particular to a method and equipment for transmitting a preamble signal. Background technique [0002] With the continuous growth of mobile data traffic, the spectrum resources are becoming more and more tight. Only using licensed spectrum resources for network deployment and service transmission may not be able to meet the traffic demand. Therefore, Long Term Evolution (LTE) systems can be considered in unlicensed Deploying transmission on spectrum resources may call this LTE system an Unlicensed LTE (Unlicensed LTE, U-LTE or LTE-U for short) system to improve user experience and expand coverage. However, there is still no clear solution on how the LTE system works on unlicensed spectrum resources. [0003] There is no specific application system planned for the unlicensed spectrum, and it can be shared by multiple wireless communication systems such as Bluetooth and WiFi. M...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26H04L5/00
CPCH04W28/16H04W74/08
Inventor 王加庆潘学明徐伟杰沈祖康
Owner DATANG MOBILE COMM EQUIP CO LTD
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