DISTRIBUTED ANTENNA SYSTEM

• US 20170126362A1
• Filed: 04/06/2016
• Published: 05/04/2017
• Est. Priority Date: 11/04/2015
• Status: Active Grant

• Current Assignee: SOLiD, Inc.
• Original Assignee: SOLiD, Inc.
• Inventors: CHO, Young Man
• Granted Patent: US 10,200,157 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04L 1/0077 Cooperative coding
• CPC Class Codes: H04L 27/0004 using wavelets

Abstract

A technology related to a distributed antenna system is disclosed. In an exemplary embodiment, a distributed antenna system may include a master unit and a plurality of remote units. The master unit may be interfaced with a wireless communications network and perform a bidirectional simultaneous digital radio frequency distribution of a wireless signal. The plurality of remote units may be each coupled to the master unit, and each perform a wireless transmission or reception of a split radio frequency signal to or from terminals located within a coverage. The master unit and the plurality of remote units may transmit or receive digital radio frequency signals in a wavelet transform domain. The master unit may determine whether the digital radio frequency signal, transmitted by each of the remote units, is normal, and merge the digital radio frequency signals.

Claims

1. A distributed antenna system, comprising:

a master unit configured to be interfaced with a wireless communications network and perform a bidirectional simultaneous digital radio frequency distribution of a wireless signal; and

a plurality of remote units configured to be coupled to the master unit and each perform a wireless transmission or reception of a split radio frequency signal to or from terminals located within a coverage,

wherein the master unit and the plurality of remote units are configured to transmit or receive digital radio frequency signals in a wavelet transform domain.

2. The distributed antenna system of claim 1, wherein the master unit is configured to determine whether the digital radio frequency signal, transmitted by each of the remote units, is normal, and merge the digital radio frequency signals.

3. The distributed antenna system of claim 2, wherein the master unit is configured to based on the digital radio frequency signals transformed to a wavelet domain, determine whether a corresponding split radio frequency signal is normal.

4. The distributed antenna system of claim 2, wherein the master unit is configured to determine whether the digital radio frequency signal, transmitted by each of the remote units, is normal, and calculate and merge a weighted sum of each radio frequency signal, of which a weight changes according to whether the digital radio frequency signal is normal.

5. The distributed antenna system of claim 2, wherein the master unit is configured to determine whether each digital radio frequency signal, transmitted by each of the remote units, is normal, and merge normal and abnormal digital radio frequency signals into respective groups.

6. The distributed antenna system of claim 1, wherein the master unit and the plurality of remote units are configured to compress the digital radio frequency signal, on which a wavelet-transform has been performed, and transmit or receive the compressed digital radio frequency signal.

7. The distributed antenna system of claim 1, wherein the distributed antenna system is configured to be coupled to the master unit on one side thereof and to another plurality of remote units on the other side thereof, and

further comprises a hub unit configured to relay digital radio frequency signals in a wavelet transform domain, which are transmitted and received between the plurality of remote units and the master unit.

8. A master unit in a distributed antenna system, the master unit comprising:

a wavelet signal processor configured to transform, to a wavelet domain, a radio frequency signal coming from a mobile communications network;

a signal splitter configured to split the digital radio frequency signal, transformed to a wavelet domain, into a plurality of digital radio frequency signals; and

a signal merger configured to merge digital radio frequency signals in a wavelet domain, which are received from a plurality of remote units; and

an inverse-wavelet signal processor configured to perform an inverse-wavelet transform on the merged digital radio frequency signal, which is then transformed to a radio frequency signal and output to a mobile communications network.

9. The master unit of claim 8, wherein the master unit further comprises:

a merge controller configured to determine whether the digital radio frequency signal, transmitted by each of the remote units, is normal, and control the merge in the signal merger.

10. The master unit of claim 9, wherein merge controller is configured to based on the digital radio frequency signal transformed to a wavelet domain, determine whether a corresponding radio frequency signal is normal.

11. The master unit of claim 9, wherein the merge controller is configured to determine whether the digital radio frequency signal, transmitted by each of the remote units, is normal, and calculate and merge a weighted sum of each digital radio frequency signal, of which a weight changes according to whether a corresponding radio frequency signal is normal.

12. The master unit of claim 9, wherein the merge controller is configured to determine whether the digital radio frequency signal, transmitted by each of the remote units, is normal, and merge normal and abnormal digital radio frequency signals into respective groups.

13. The master unit of claim 8, further comprising:

a compressor configured to compress a digital radio frequency signal, transformed to a wavelet domain, between the wavelet signal processor and the signal splitter; and

a decompressor configured to decompress a merged digital radio frequency signal in a wavelet domain between the signal merger and the inverse-wavelet signal processor.

14. A remote unit in a distributed antenna system, the remote unit comprising:

an upper transceiver configured to transmit or receive digital radio frequency signals in a wavelet domain to or from an upper node;

an inverse-wavelet signal processor configured to perform an inverse-wavelet transform on the digital radio frequency signals, output from the upper transceiver, which is then transformed to a split radio frequency signal and output to an antenna; and

a wavelet signal processor configured to transform the radio frequency signal, received from the antenna, to a wavelet domain, which is then output to the upper transceiver.

15. The remote unit of claim 14, further comprising:

a lower transceiver configured to output the digital radio frequency signal, received from a lower node, to the upper transceiver, and output the digital radio frequency signal, received from the upper node, to the lower node; and

a signal splitter configured to split the digital radio frequency signal received from the upper transceiver to the inverse-wavelet signal processor and a lower transceiver,

wherein the upper transceiver is configured to multiplex the digital radio frequency signals, which are received from the lower transceiver and output from the wavelet signal processor, and transmit the multiplexed digital radio frequency signal to the upper node.

16. The remote unit of claim 14, further comprising:

a lower transceiver configured to transmit or receive the digital radio frequency signal to or from a lower node;

is a signal splitter configured to split the digital radio frequency signal, received from the upper transceiver, to an inverse-wavelet signal processor and a lower transceiver; and

a signal merger configured to merge the digital radio frequency signals, which are output from the wavelet signal processor and output from the lower transceiver, and output the merged digital radio frequency signal to the upper transceiver.

17. The remote unit of claim 16, further comprising:

a state determiner configured to determine whether the digital radio frequency signal, transmitted by each of the remote units, is normal.

18. The remote unit of claim 17, wherein the state determiner is configured to determine whether the digital radio frequency signal is normal based on the digital radio frequency signal transformed to a wavelet domain.

19. The remote unit of claim 16, further comprising:

a decompressor configured to decompress a merged digital radio frequency signal in a wavelet domain between the signal splitter and the inverse-wavelet signal processor; and

a compressor configured to compress a digital radio frequency signal, transformed to a wavelet domain, between the wavelet signal processor and the signal merger.

20. The remote unit of claim 14, further comprising:

a decompressor configured to receive and decompress the digital radio frequency signal, transformed to a wavelet domain, and output the decompressed digital radio frequency signal to the inverse-wavelet signal processor; and

a compressor configured to compress a digital radio frequency signal transformed to a wavelet domain, which is output from the wavelet signal processor.