METHOD AND SYSTEM FOR CPRI CASCADING IN DISTRIBUTED RADIO HEAD ARCHITECTURES

• US 20110237178A1
• Filed: 03/24/2010
• Published: 09/29/2011
• Est. Priority Date: 03/24/2010
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Network Communications Incorporated (Fujitsu Limited)
• Inventors: Seki, Hiroyuki, Kiyanagi, Hiroyuki, Mao, Nien-Tai Kai, Chen, Wei-Peng, Zhu, Chenxi
• Granted Patent: US 8,467,823 B2
• Time in Patent Office: Days
• US Class Current: 455/3.01
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

A method of communicating between a base band unit and a plurality of remote radio heads includes the steps of receiving a first signal through an antenna in a first remote radio head, transmitting the first signal to a second remote radio head through a digital radio interface, receiving a second signal through an antenna in the second remote radio head, compensating for a delay accrued in the first signal, adding the first signal and the second signal to obtain a resulting signal, and transmitting the resulting signal to a base band unit through a digital radio interface.

Claims

1. A method of communicating between a base band unit and a plurality of remote radio heads, comprising the steps of:

receiving a first signal through an antenna in a first remote radio head;

transmitting the first signal to a second remote radio head through a digital radio interface;

receiving a second signal through an antenna in the second remote radio head;

compensating for a delay accrued in the first signal;

adding the first signal and the second signal to obtain a resulting signal; and

transmitting the resulting signal to a base band unit through a digital radio interface.

5. The method of claim 1, wherein the first signal is compensated for the delay accrued in the first signal.

6. The method of claim 1, wherein the second signal is compensated for the delay accrued in the first signal.

7. The method of claim 1, wherein the delay accrued in the first signal comprises delay due to transmission of first signal to the second remote radio head.

8. The method of claim 7, wherein the delay accrued in the first signal further comprises delay due to transmission of a third signal to the second remote radio head.

2. The method of claim 2, wherein the digital radio interface is CPRI.

3. The method of claim 2, wherein adding the first signal and the second signal to obtain a resulting signal further comprises using digital signal bits addition.

4. The method of claim 3, wherein using digital signal bits addition further comprises utilizing a fifteen-bit word.

9. An article of manufacture comprising:

a computer readable medium; and

computer-executable instructions carried on the computer readable medium, the instructions readable by a processor, the instructions, when read and executed, for causing the processor to;

receive a first signal through an antenna in a first remote radio head;

transmit the first signal to a second remote radio head through a digital radio interface;

receive a second signal through an antenna in the second remote radio head;

compensate for a delay accrued in the first signal;

add the first signal and the second signal to obtain a resulting signal; and

transmit the resulting signal to a base band unit through a digital radio interface.

10. The article of claim 9, wherein the digital radio interface is CPRI.

11. The article of claim 9, wherein adding the first signal and the second signal to obtain a resulting signal further comprises using digital signal bits addition.

12. The article of claim 11, wherein using digital signal bits addition further comprises utilizing a fifteen-bit word.

13. The article of claim 9, wherein the first signal is compensated for the delay accrued in the first signal.

14. The article of claim 9, wherein the second signal is compensated for the delay accrued in the first signal.

15. The article of claim 9, wherein the delay accrued in the first signal comprises delay due to transmission of first signal to the second remote radio head.

16. The article of claim 15, wherein the delay accrued in the first signal further comprises delay due to transmission of a third signal to the second remote radio head.

18. The system of claim 9, wherein the digital radio interface is CPRI.

17. A system for telecommunications, comprising:

a base band unit;

a backhaul network, the backhaul network coupled to the base band unit; and

,

a cascaded chain of remote radio heads, the cascaded chain of remote radio heads comprising;

a first remote radio head coupled to a first set of one or more antennas;

a second remote radio head coupled to a second set of one or more antennas, the second remote radio head coupled to the first remote radio head through optical fiber; and

,

wherein the cascaded chain of remote radio heads is coupled to the backhaul network;

wherein;

the base band unit communicates through a digital radio interface with the first remote radio head over the backhaul network;

the first remote radio head communicates through the digital radio interface with the second remote radio head;

the second remote radio head is configured to receive signals from the second set of antennas and communicate the signal to the first remote radio head; and

the first remote radio head is configured to;

receive a first signal from the first set of antennas;

receive a second signal from the second remote radio head;

compensate for a delay accrued in the second signal;

add the first signal and second signal to obtain a resulting signal; and

transmit the resulting signal to the base band unit through a digital radio interface.

19. The system of claim 17, wherein adding the first signal and the second signal to obtain a resulting signal further comprises using digital signal bits addition.

20. The system of claim 19, wherein using digital signal bits addition further comprises utilizing a fifteen-bit word.

21. The system of claim 17, wherein the first signal is compensated for the delay accrued in the first signal.

22. The system of claim 17, wherein the second signal is compensated for the delay accrued in the first signal.

23. The system of claim 17, wherein the delay accrued in the first signal comprises delay due to transmission of first signal to the second remote radio head.

24. The system of claim 23, wherein the delay accrued in the first signal further comprises delay due to transmission of a third signal to the second remote radio head.