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Access method, terminal and base station of orthogonal frequency division multiplexing (OFDM) system

A technology of orthogonal frequency division and access method, which is applied in the field of terminal and base station, and access method of OFDM system, which can solve the problems of lowering the overall performance of the system and poor access performance of the new system, and achieve expansion Number, effect of improving access performance

Inactive Publication Date: 2014-01-01
ZTE CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] In view of this, the present invention provides a method for accessing an OFDM system, which is used to solve the problem of poor access performance or poor access performance of the new system due to the complete use of the synchronization channel of the old system or the use of a new synchronization channel. Issues that degrade overall system performance

Method used

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  • Access method, terminal and base station of orthogonal frequency division multiplexing (OFDM) system
  • Access method, terminal and base station of orthogonal frequency division multiplexing (OFDM) system
  • Access method, terminal and base station of orthogonal frequency division multiplexing (OFDM) system

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0118] In this embodiment, the P-SCH bandwidth of 16m is 5MHz, and the P-SCH has a total of 20 sequences x(n) to carry mode information and Cell ID group information, and the available subcarrier N used =The even-numbered positions on the 432 subcarriers are alluded to, and the odd-numbered positions of the subcarriers can be set to zero. which is:

[0119] x(n)=x(2k), n=2k, k=1, 2, 3,...

[0120] x(n)=x(2k+1)==0, n=2k+1, k=1, 2, 3,...

[0121] Among n=2k subcarriers (even subcarriers), it is further divided into two groups of subcarriers group 1 and group 2, where group 1 is located in subcarriers:

[0122] n=4k

[0123] Group 2 is located on subcarriers:

[0124] n=4k+2

[0125] Modulation on group 1 subcarriers Modulation on group 2 subcarriers (can be composed of 4 and 5 A total of 20 x(n) sequences are constructed), and the rest of the subcarriers are set to zero, such as Figure 7 shown in Figure 7 The middle arrow indicates that the position carries a s...

Embodiment 2

[0130] The difference between this embodiment and Embodiment 1 is that this embodiment further divides n=2k subcarriers (even-numbered subcarriers) into two groups of subcarriers group 1 and group 2, wherein group 1 is located in the subcarrier Set c1, group 2 is in subset c2, the total number of subcarriers in subset c1 is N used / 4, the total number of subcarriers in subset c2 is N used / 4, the subset c1 has no intersection with the subset c2. Such as Image 6 shown.

[0131] base station will mapped in subset c1, mapped in subset c2. The remaining subcarriers are set to zero.

[0132] The x(n) obtained by mapping in this way is changed through IFFT, that is, the transmitted P-SCH symbol is obtained, and the SCH symbol is sent to the terminal through the P-SCH.

[0133] At the receiving end (that is, the terminal), first generate the local sequence of the P-SCH, and the generation method of the local sequence is: first modulate on the group 1 subcarrier The remain...

Embodiment 3

[0136] The difference between this embodiment and Embodiment 1 is that in this embodiment, in subcarriers (even subcarriers) of n=2k of P-SCH, the modulation sequence is:

[0137]

[0138] in L=N used / 2,

[0139] The sequence x(n) mapped in this way is changed through IFFT, that is, the symbol of the transmitted P-SCH is obtained.

[0140] At the receiving end, a plurality of local sequences are firstly generated. The local sequence generation method is as follows: first, modulate x(n) on n=2k subcarriers (even-numbered subcarriers), and set the rest of the subcarriers to zero. The x(n) mapped by the mode is changed by IFFT to obtain the time-domain signal of the local sequence. Finally, time synchronization can be obtained by performing CC between the time domain signal of the local sequence and the received signal. Since the IFFT of x(n) is The time-domain offset of the IFFT, so although the number of sequences increases, the time-domain sequence content is the ...

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Abstract

The invention discloses an access method, a terminal and a base station of an orthogonal frequency division multiplexing (OFDM) system. In the method, the terminal firstly receives information sent by the base station through synchronization channels, wherein the synchronization channels comprise a primary synchronization channel and a secondary synchronization channel, wherein the primary synchronization channel is used for transmitting pattern information and grouping information of cell identification codes, and the secondary synchronization channel is used for transmitting group internal information of the cell identification codes; and then, the terminal synchronizes and demodulates the pattern information of the system according to the primary synchronization channel, and detects the cell identification codes according to the grouping information of the cell identification codes received by the primary synchronization channel and the group internal information of the cell identification codes received by the secondary synchronization channel. By utilizing the technical scheme provided by the invention, the number of the cell identification codes can be increased, and the access performance of the system can be improved.

Description

technical field [0001] The present invention relates to the technical field of mobile communication, in particular to an access method, terminal and base station of an orthogonal frequency division multiplexing system. Background technique [0002] Orthogonal Frequency Division Multiplex (OFDM for short) is a multi-carrier transmission mode that converts a high-speed transmission data stream into a set of low-speed parallel transmission data streams. Sensitivity to multipath fading channel frequency selectivity, improving bandwidth utilization, and, because of the introduction of a cyclic prefix, further enhancing the ability of the system to resist Inter-symbol Interference (abbreviated as ISI). Moreover, due to the simple implementation of OFDM technology, OFDM has become more and more widely used in wireless communication domains, for example, wireless local area network (Wireless Local, referred to as WLAN) system, 802.16e based on Orthogonal Frequency Division Multiple ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/26H04B7/204
Inventor 孙长印姚珂方惠英卢科学
Owner ZTE CORP