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Frame creating method based on crossing frequency division multiplexing in time-division duplex mode

An orthogonal frequency division and time division duplex technology, applied in the field of digital communication, can solve the problems of not having to consider the problem of ultra-long coverage, the change of the number of accesses, and the frame structure that does not meet the requirements of future communication, etc., and achieves low sensitivity , ISI) strong effect

Active Publication Date: 2007-02-07
SHANGHAI MUNICIPAL ELECTRIC POWER CO
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  • Description
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  • Application Information

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Problems solved by technology

At the same time, its uplink access time is fixed, which is not conducive to the flexible configuration of access, for example, it cannot meet the change of access number in different time periods, the change of access slot length in different coverage, etc.
[0007] For the WiMAX system, although it fully considers the characteristics of OFDM technology, but because it does not need to consider the problem of ultra-long-distance coverage, its frame structure also does not meet the requirements for future communication.

Method used

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  • Frame creating method based on crossing frequency division multiplexing in time-division duplex mode
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  • Frame creating method based on crossing frequency division multiplexing in time-division duplex mode

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no. 1 example

[0032] first please refer to figure 2 Understand the frame structure based on OFDM technology in the TDD mode generated in this embodiment, the wireless frame is used for wireless transmission between the base station and the mobile station, and then describe the method for generating the frame structure.

[0033] Such as figure 2 As shown, the radio frame in this embodiment adopts a three-layer structure: radio frame, subframe, and time slot. In order to be compatible with the existing W-CDMA and TD-SCDMA systems, the wireless frame of this embodiment is consistent with the wireless frame length of W-CDMA, which is 10 ms, and then divided into two 5 ms subframes with the same structure. Each subframe includes a part for transmitting service data, a downlink synchronization part, an uplink synchronization part, and a switching interval between downlink and uplink and uplink to downlink. But the order of each part is different from the frame structure of systems such as TD-...

no. 2 example

[0045] The frame structure of this embodiment and its generation method are basically the same as those of the first embodiment, such as image 3 As shown, the only differences are in the following points:

[0046] First, the downlink synchronization symbol in this embodiment is independent of the time slot structure, but is generated before the time slot TS0.

[0047] Second, in order to meet the requirements of 30km or even 100km ultra-long coverage and avoid the waste of too long DUG in the case of non-ultra-long coverage, the base station of this embodiment can also generate at the front end of time slot TS1 or the back end of time slot TS0 according to the business situation Idle symbol (that is, an empty symbol, not shown in the figure), so that a shorter DUG can be designed, and this DUG only needs to meet the non-ultra-distance coverage situation.

[0048] Whether the specific insertion position is the back end of TS0 or the front end of TS1 is determined by the posit...

no. 3 example

[0051] The aforementioned frame structures of the first and second embodiments can meet general delay requirements. When there is a more stringent delay requirement (such as when the delay requirement is less than 10ms), the structure of this embodiment can be adopted, such as Figure 4 shown.

[0052] The frame structure and its generation method of this embodiment are basically the same as those of the first embodiment, the only difference being the following points:

[0053] First, the downlink synchronization symbol of this embodiment is inserted inside the time slot structure, at the front end of the time slot TS0, as a component of the TS0.

[0054] Second, this embodiment adds a flexible configuration symbol (FS: FlexibleSymbol) at the end of several time slots. The end symbol of the slot is still used to transmit service data. Combined with the main switching interval, this symbol constitutes multiple switching points, which can realize multiple switching between up...

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Abstract

The invention relates to a method for generating the frame under time division duplex mode, based on orthogonal frequency division multiplexing technique, to be used in wireless transmission between base station and mobile station, wherein it divides the time length of one sub frame into several ascending and descending time slits with same length; using the first time slit TS0 as the broadcast time slit and the second time slit TS1 as ascending time slit; in the descending time slit, using orthogonal frequency division multiplexing method to form the transmitted data; before the time slit TS1, building the descending synchronous mark and inserting ascending synchronous unit into the time slit TS1; after the time slit TS0 and before the TS1, generating DUG, and based on the demands of ascending and descending services, after the time slit TS1, generating UDG, to realize the conversion between ascending and descending; then combining obtained several sub frames, to obtain one frame. The inventive frame structure combines the advantages of TDD mode and OFDM technique.

Description

technical field [0001] The invention relates to the field of digital communication, in particular to a frame structure based on Orthogonal Frequency Division Multiplexing (OFDM) technology in Time Division Duplex (TDD) mode and a generating method thereof. Background technique [0002] In order to keep its wireless communication technology competitive in the next ten years or longer, 3GPP has proposed a long-term evolution (LTE) plan. Its requirements mainly include high user data rate, high spectrum utilization, low delay, support for high mobility, and wide coverage. However, these requirements are consistent with the future communication system, because future data services will become more and more colorful, which requires the system to provide higher transmission rates. The call for global digital equality requires the system to consider the needs of ultra-long-distance coverage. to bridge the global digital divide. [0003] Orthogonal frequency division multiplexing ...

Claims

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Application Information

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IPC IPC(8): H04L27/26H04L5/26H04J13/02H04L25/03
Inventor 毕东艳郁光辉胡留军赵盟夏树强
Owner SHANGHAI MUNICIPAL ELECTRIC POWER CO
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