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Diversity transmission method and device of OFDM (Orthogonal Frequency Division Multiplexing) system

A technology of diversity transmission and grouping, applied in the field of communication, can solve problems such as affecting system performance and poor space diversity effect, and achieve the effect of improving space diversity effect

Active Publication Date: 2010-11-03
HUAWEI TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, antenna port 0 is always paired with antenna port 2, and antenna port 1 is always paired with antenna 3. The space diversity effect is not good. If antenna port 0 and antenna port 2 or antenna port 1 and antenna port 3 are connected simultaneously within a wide frequency range Deep fading also affects system performance

Method used

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  • Diversity transmission method and device of OFDM (Orthogonal Frequency Division Multiplexing) system
  • Diversity transmission method and device of OFDM (Orthogonal Frequency Division Multiplexing) system
  • Diversity transmission method and device of OFDM (Orthogonal Frequency Division Multiplexing) system

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Embodiment 1

[0036] In this embodiment, the number of antenna ports M is 4, and the number of subcarriers N in each group is also 4. The pilot density of antenna ports 0 and 1 in this embodiment is twice that of antenna ports 2 and 3. The following is the detailed process of the space-frequency coding of this embodiment in this case:

[0037] Step S201: For an OFDM system with 4 transmitting antennas, divide the 4 OFDM subcarriers into one group and record its number as k, where k is an integer whose initial value is 0.

[0038] Step 202: If k mod 2 = 0, its subcarrier mapping method is shown in the following formula, the element S in the matrix 1 , S 2 etc. represent the transmitted symbols, where the horizontal direction represents the subcarrier used by each antenna port, and the vertical direction represents the antenna port.

[0039] S 1 S 2 ...

Embodiment 2

[0044] In this embodiment, the number of antenna ports M is 4, and the number of subcarriers N in each group is an integer multiple of 4, such as N=8. In this embodiment, the pilot density of antenna ports 0 and 1 is twice that of antenna ports 2 and 3 . The following is the detailed process of the space-frequency coding of this embodiment in this case:

[0045]Step S301: For an OFDM system with 4 transmitting antennas, divide 8 OFDM subcarriers into one group, and record its number as k, where k is an integer whose initial value is 0.

[0046] Step 302: Divide the 8 subcarriers into 4 subcarriers in each group. If k mod 2 = 0, the mapping method for each 4 subcarriers is shown in the following formula, where the horizontal direction represents subcarriers, and the vertical direction represents antenna ports.

[0047] S 1 S 2 ...

Embodiment 3

[0052] In this embodiment, the number of antenna ports M is 4, and the number of subcarriers N in each group is an integer multiple of 4, such as N=8. And N is the number of subcarriers available for 1 OFDM symbol. In this embodiment, one subcarrier mapping method is used for round-robin transmission for the same OFDM symbol, and another sub-carrier mapping method is used for adjacent symbols to perform round-robin transmission. In this embodiment, the pilot density of antenna ports 0 and 1 is twice that of antenna ports 2 and 3 . The following is the detailed process of the space-frequency coding of this embodiment in this case:

[0053] Step S401: For a 4-antenna OFDM system, divide N OFDM subcarriers into one group, and record its number as k, where k is an integer whose initial value is 0. Wherein N is the number of subcarriers available for 1 OFDM symbol. Optionally, N OFDM subcarriers are defined as continuous subcarriers from small to large in the frequency domain on...

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Abstract

The embodiment of the invention provides diversity transmission method and device of an OFDM (Orthogonal Frequency Division Multiplexing) system. The method comprises the steps of: grouping OFDM subcarriers, wherein the number N of subcarriers in each group is an integral multiple of the number M of antenna port, and M is an integral multiple of 4; carrying out space frequency coding with SFBC (Space Frequency Block Code)+FSTD (Frequency Switch Transmit Diversity) on N subcarriers in each group at M antenna ports, wherein different subcarrier mapping modes are adopted on the subcarriers in odd number groups and the subcarriers in even number groups; and carrying out diversity transmission on data symbols of M antenna ports according to a space frequency coding result. The embodiment of the invention improves the space diversity effect through a mode of alternatively using different subcarrier mapping modes, thereby avoiding the situation that because of the adoption of a fixed mapping mode, the link performance is influenced when deep fading occurs in a wider frequency band range.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a method and device for diversity transmission of an OFDM system. Background technique [0002] In 3GPP LTE (Long Term Evolution, Long Term Evolution) Release 8, the downlink control channel data channel 4-antenna diversity scheme uses SFBC (Space-Frequency Block Code, space-frequency coding) + FSTD (Frequency Switch Transmit Diversity, frequency switching transmit diversity) for Space-frequency coding and diversity transmission. Specifically include: Divide the 4 adjacent subcarriers into 2 groups, for the first group of 2 adjacent OFDM subcarriers, 2 transmit symbols are used for diversity coding on 2 antennas; for the second group of 2 adjacent OFDM subcarriers Carrier, the other 2 transmit symbols are diversity coded on the other 2 antennas. An optional encoding method is as follows: [0003] y ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26H04B7/02
Inventor 文雪汪凡
Owner HUAWEI TECH CO LTD
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