ROF link apparatus capable of stable TDD wireless service

• US 7,733,825 B2
• Filed: 09/01/2006
• Issued: 06/08/2010
• Est. Priority Date: 09/02/2005
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Choi, Dae-Eun, Lee, Jae-Hoon, Hwang, Seong-Taek, Kim, Hoon, Oh, Yun-Je, Kim, Sang-Ho, Kim, Byung-Jik, Kim, Sung-Kee, Lee, Han-Lim, Kim, Yong-Gyoo, Lee, Gyu-Woong
• Primary Examiner(s): Harper; Kevin C
• Assistant Examiner(s): WOOD, JR, STEVEN A
• Application Number:
  US11/514,440
• Publication Number:
  US 20070053311A1
• Time in Patent Office: 1,376 Days
• Field of Search: None
• US Class Current: 370/328
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

A radio over fiber (ROF) link apparatus capable of a stable TDD wireless service for a time division duplexing (TDD) baseband signal includes a central access platform (CAP) for receiving various kinds of data including the TDD baseband signal from upper layers, multiplexing the data, electro-optically converting the multiplexed data, and transmitting the converted data as downstream data through an optical fiber, and opto-electrically converting upstream data received through the optical fiber, demultiplexing the converted upstream data, and transmitting the demultiplexed upstream data to the respective upper layers, and a remote access unit (RAU) for receiving the downstream data through the optical fiber, opto-electrically converting the received downstream data to the multiplexed data, demultiplexing the multiplexed data, performing a wireless access process of the demultiplexed data, and transmitting the wireless access processed data to a wireless local area network (WLAN) service terminal through an antenna.

Claims

1. A radio over fiber (ROF) link apparatus for providing a stable TDD wireless service for a time division duplexing (TDD) baseband signal, the ROF link apparatus comprising:

a central access platform (CAP) for;

receiving various kinds of data including the TDD baseband signal from upper layers,

multiplexing the data,

electro-optically converting the multiplexed data, and

transmitting the converted data as downstream data through an optical fiber; and

a remote access unit (RAU) for;

receiving the downstream data through the optical fiber,

opto-electrically converting the received downstream data to the multiplexed data,

demultiplexing the multiplexed data,

performing a wireless access process of the demultiplexed data, and

transmitting the wireless access processed data to a wireless local area network (WLAN) service terminal through an antenna;

wherein the CAP does not have WLAN Access Points (APs) disposed therein for TDD communications and the RAU includes a TDD access point (AP) for processing a TDD baseband signal among the demultiplexed signals to an RF signal for WLAN communication; and

wherein the CAP includes;

a TDD processing unit for receiving the TDD baseband signal from the upper layer and downstream processing the received TDD baseband signal;

a plurality of radio frequency (RF) processing units for receiving RF signals from the upper layers and downstream processing the received RF signals;

a multiplexer for multiplexing signals separately output from the TDD processing unit to the multiplexer and from the plurality of RF processing units to the multiplexer into a single electrical signal;

a first electro-optical converter for converting the electrical signals multiplexed by the multiplexer to an optical signal; and

a transmitter for transmitting the converted optical signal through the optical fiber.

2. The ROF link apparatus of claim 1, wherein the RAU comprises:

an opto-electrical converter for converting the optical signal received through the optical fiber to an electrical signal;

a demultiplexer for demultiplexing the electrical signal converted by the optoelectrical converter to signals;

a plurality of RF amplifiers for amplifying RF signals among the demultiplexed signals;

a coupler for coupling the RF signals output from the plurality of RF amplifiers and the TDD AP to a single signal; and

a transmitter for outputting the single signal to the WLAN service terminal through the antenna.

3. The ROF link apparatus of claim 1, wherein the CAP comprises:

a TDD processing unit for receiving the TDD baseband signal from the upper layer and downstream processing the received TDD baseband signal;

an intermediate frequency (IF) modulator for modulating a baseband signal output from the TDD processing unit to an IF signal;

a plurality of RF processing units for receiving RF signals from the upper layers and downstream processing the received RF signals;

a multiplexer for multiplexing signals output from the IF modulator and the plurality of RF processing units to a single electrical signal;

a first electro-optical converter for converting the multiplexed electrical signals to an optical signal; and

a transmitter for transmitting the converted optical signal through the optical fiber.

4. The ROF link apparatus of claim 3, wherein the RAU comprises:

an opto-electrical converter for converting the optical signal received through the optical fiber to an electrical signal;

a demultiplexer for demultiplexing the electrical signal converted by the opto-electrical converter to signals;

a plurality of RF amplifiers for amplifying RF signals among the demultiplexed signals;

an IF demodulator for demodulating an IF signal among the demultiplexed signals to a TDD baseband signal;

a TDD AP for receiving the TDD baseband signal demodulated by the IF demodulator and processing the TDD baseband signal to an RF signal for WLAN communication;

a coupler for coupling the RF signals output from the plurality of RF amplifiers and the TDD AP to a single signal; and

a transmitter for outputting the single signal to the WLAN service terminal through the antenna.

5. The ROF link apparatus of claim 2, wherein the TDD processing unit performs a media conversion function of converting a 100 Base-TX signal, which is the baseband signal received from the upper layer, to a 100 Base-FX signal, which is a baseband signal for optical modulation.

6. The ROF link apparatus of claim 5, wherein the RAU further comprises:

a media converter in a front-end of the TDD AP to convert the 100 Base-FX signal, which is the baseband signal for optical modulation, to the 100 Base-TX signal, which is the baseband signal received from the upper layer.

7. The ROF link apparatus of claim 5, wherein the TDD AP of the RAU performs a function of converting the 100 Base-FX signal, which is the baseband signal for optical modulation, to the 100 Base-TX signal, which is the baseband signal received from the upper layer.

8. The ROF link apparatus of claim 1, wherein an extinction ratio of the TDD baseband signal is lowered not to affect the TDD baseband signal or the RF signals in a process of modulating the TDD baseband signal and the RF signals to a single optical signal.

9. The ROF link apparatus of claim 1, the CAP further for:

optoelectric converting upstream data received through the optical fiber,

demultiplexing the converted upstream data, and

transmitting the demultiplexed upstream data to the respective upper layers; and

wherein the TDD process unit and each one RF processing units of the plurality of RF processing units are directly coupled to the multiplexer.