Method, system, base station and user equipment determining cyclic delay and diversity delay

A cyclic delay diversity, user equipment technology, applied in diversity/multi-antenna system, multi-frequency code system, space transmit diversity and other directions, can solve problems such as slightly poor performance

Inactive Publication Date: 2009-02-04
NTT DOCOMO INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

From a performance point of view, in codebook-based precoding, the precoding coefficients are selected from several pre-calculated coefficients, so it cannot be guaranteed to be optimal at every moment. Usually, code-based The performance of the book precoding technique is slightly worse than the performance of the optimal non-codebook precoding technique

Method used

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  • Method, system, base station and user equipment determining cyclic delay and diversity delay
  • Method, system, base station and user equipment determining cyclic delay and diversity delay
  • Method, system, base station and user equipment determining cyclic delay and diversity delay

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Embodiment 1

[0217] In this embodiment, the receiving end, that is, the user equipment (UE), obtains the CDD delay value (group) in its own optimal precoding codebook, and feeds it back to the base station (BS), and then the transmitting end, that is, the base station, according to the collected The CDD delay value (group) in the optimal precoding codebook from each user equipment, select the CDD delay value (group) in the global precoding codebook to realize the CDD delay value in the precoding codebook ( Group) adaptive update, so as to maximize the protection of system performance. Global here means that the CDD delay value (group) in the same group of precoding codebooks is applicable to all users. For convenience of description, both the CDD delay value and the group of CDD delay values ​​are referred to as CDD delay values. refer to figure 2 , in a multi-user scheduling MIMO-OFDMA system including a base station and several user equipments and applying a precoding technology combi...

Embodiment 2

[0257] In this embodiment, the receiving end, that is, the user equipment, obtains its own channel characteristic information, and then the transmitting end, that is, the base station, according to the collected channel characteristic information from each user equipment, reasonably selects the CDD delay value in the global precoding codebook , to realize the adaptive update of the CDD delay value in the precoding codebook, so as to guarantee the system performance to the greatest extent. refer to Figure 5 , in a multi-user scheduling MIMO-OFDMA system including a base station and several user equipments and applying a precoding technology combined with CDD, the method described in the embodiment of the present invention includes the following steps:

[0258] Step 501, the base station sends a start signal to the user equipment to start the update process of the CDD delay value in the precoding codebook, or the user equipment periodically automatically starts the update proce...

Embodiment 3

[0297] In this embodiment, the receiving end, that is, the user equipment, obtains the CDD delay value in its own optimal precoding codebook, and feeds it back to the base station, and then the transmitting end, that is, the base station, according to the optimal delay value collected from each user equipment The CDD delay value in the precoding codebook, select the optimal CDD delay value in the precoding codebook for each user to realize the adaptive update of the CDD delay value in the precoding codebook, and it is independent for each user The CDD delay value in the precoding codebook is updated accurately, so as to guarantee the system performance to the greatest extent. refer to Figure 8 , in a multi-user scheduling MIMO-OFDMA system including a base station and several user equipments and applying a precoding technology combined with CDD, the method described in the embodiment of the present invention includes the following steps:

[0298] Step 801, the base station s...

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Abstract

The invention discloses a plurality of methods to determine a delay value of cyclic delay diversity as well as a system, a base station and a user equipment. One of the methods includes: A1. The user equipment gets the CDD delay values in a pre-coding code book which can achieve the best channel quality on each sub-band according to the channel estimation result and feeds back the values to the base station; A2. The base station selects the global CDD delay values in the pre-coding code book according to the received CDD delay values in the best local pre-coding code book from each user equipment; A3. The base station updates the CDD delay values in the pre-coding code book according to the selected global CDD delay values in the pre-coding code book. The invention provides methods, the system, the base station and the user equipment to determine the CDD delay values (groups) in a pre-coding system combining with CDD, and realizes the adaptive update of the CDD delay values (groups) so as to provide guarantee for the system performance to the maximum.

Description

technical field [0001] The present invention relates to multiple-input multiple-output-orthogonal frequency division multiple access (MIMO-OFDMA) system, in particular, relates to the application combined with cyclic delay diversity (Cyclic DelayDiversity, CDD) precoding (precoding) technology in MIMO-OFDMA system When performing multi-user scheduling, a method, system, base station and user equipment for determining CDD delay values ​​(groups) in a precoding codebook. Background technique [0002] With the wide application and continuous development of the MIMO-OFDMA system, the performance of the system is further improved by introducing a precoding technology based on cyclic delay diversity. [0003] The precoding technology is an effective method for improving system performance. This method can reduce the complexity of the receiving end and improve the system performance by preprocessing the signal at the sending end. Especially when the system works in the downlink sp...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04B7/04H04L27/26H04J11/00
Inventor 刘竞秀佘小明陈岚
Owner NTT DOCOMO INC
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