Data transmission method and related device and system

• US 8,873,657 B2
• Filed: 09/13/2013
• Issued: 10/28/2014
• Est. Priority Date: 03/15/2011
• Status: Expired due to Fees

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Liu, Sheng, Yu, Rongdao, Wang, Rui
• Primary Examiner(s): TSE, YOUNG TOI
• Application Number:
  US14/026,865
• Publication Number:
  US 20140029952A1
• Time in Patent Office: 410 Days
• Field of Search: 375/260, 375/261, 375/262, 375/265, 375/267, 370/208, 370/210, 370/337, 370/344, 398/128, 398/130, 398/135, 398/138, 398/140, 398/182, 398/200, 398/201, 398/202, 398/207, 398/212, 398/214
• US Class Current: 375/260
• CPC Class Codes: H04B 10/116 Visible light communication
• CPC Class Codes: H04B 10/40 Transceivers
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04L 27/0008 arrangements for allowing a transmitter or receiver to use more than one type of modulation negotiating modulation type for two-way transmission paths H04L5/1453
• CPC Class Codes: H04L 27/2605 Symbol extensions, e.g. Zero Tail, Unique Word [UW]
• CPC Class Codes: H04L 27/2697 in combination with other modulation techniques
• CPC Class Codes: H04L 5/0023 Time-frequency-space

Abstract

Embodiments of the present invention disclose a data transmission method and a related device and system. A data transmission method includes: A transmitter performs scrambling, constellation modulation, and multiple-input multiple-output precoding processing sequentially on downlink user data to obtain a precoded symbol sequence; performs time-frequency resource mapping on the precoded symbol sequence to obtain frequency domain data of an OFDM symbol; performs conjugate symmetric extension and IFFT on the frequency domain data of the OFDM symbol to obtain a time domain real-number sequence; performs CP insertion processing on the time domain real-number sequence to form a first downlink time domain baseband signal; loads the first downlink time domain baseband signal onto a direct current of a LED lighting circuit to form a LED driving electrical signal; and converts the LED driving electrical signal into a visible beam of the LED for transmission.

Claims

1. A data transmission method, comprising:

performing, by a transmitter, scrambling, constellation modulation, and multiple-input multiple-output precoding processing sequentially on downlink user data to obtain a precoded symbol sequence;

performing, by the transmitter, time-frequency resource mapping on the precoded symbol sequence to obtain frequency domain data of an orthogonal frequency division multiplexing symbol;

performing, by the transmitter, conjugate symmetric extension and inverse fast Fourier transform on the frequency domain data of the orthogonal frequency division multiplexing symbol to obtain a time domain real-number sequence;

performing, by the transmitter, cyclic prefix insertion processing on the time domain real-number sequence to form a first downlink time domain baseband signal;

loading, by the transmitter, the first downlink time domain baseband signal onto a direct current of a light-emitting diode lighting circuit to form a light-emitting diode driving electrical signal; and

converting, by the transmitter, the light-emitting diode driving electrical signal into a visible beam of the light-emitting diode for transmission.

2. The data transmission method according to claim 1, further comprising:

receiving, by the transmitter, a first upper-layer scheduling command before performing the conjugate symmetric extension on the frequency domain data of the orthogonal frequency division multiplexing symbol, wherein the first upper-layer scheduling command is used to instruct the transmitter to use a visible light communication mode to transmit data.

3. The data transmission method according to claim 2, when the transmitter receives a second upper-layer scheduling command, wherein the second upper-layer scheduling command is used to instruct the transmitter to use a radio frequency communication mode to transmit data, after the transmitter obtains the frequency domain data of the orthogonal frequency division multiplexing symbol, the method further comprising:

performing the inverse fast Fourier transform and the cyclic prefix insertion processing on the frequency domain data of the orthogonal frequency division multiplexing symbol to form a second downlink time domain baseband signal, and transmitting the second downlink time domain baseband signal through a radio frequency.

4. The data transmission method according to claim 1, further comprising:

receiving, by a receiver, the visible beam of the light-emitting diode and performing optical-to-electrical conversion to obtain the first downlink time domain baseband signal;

performing, by the receiver, cyclic prefix removal, fast Fourier transform, and conjugate symmetry removal processing on the obtained first downlink time domain baseband signal to obtain the frequency domain data of the orthogonal frequency division multiplexing symbol;

performing, by the receiver, resource demapping on the obtained frequency domain data of the orthogonal frequency division multiplexing symbol to obtain the precoded symbol sequence; and

performing, by the receiver, multiple-input multiple-output detection, channel equalization, constellation demodulation, and descrambling processing on the obtained precoded symbol sequence sequentially to obtain the downlink user data.

5. The data transmission method according to claim 1, wherein:

after the transmitter performs the cyclic prefix insertion processing on the time domain real-number sequence to form the first downlink time domain baseband signal, the method further comprising;

performing amplification and pre-distortion processing on the first downlink time domain baseband signal; and

the loading, by the transmitter, the first downlink time domain baseband signal onto the direct current of the light-emitting diode lighting circuit to form the light-emitting diode driving electrical signal comprises;

loading the first downlink time domain baseband signal after the amplification and pre-distortion processing onto the direct current of the light-emitting diode lighting circuit to form the light-emitting diode driving electrical signal.

6. The data transmission method according to claim 1, wherein:

the light-emitting diode is located in any one light-emitting diode light group that is formed by at least two light-emitting diodes, wherein a visible beam of each light-emitting diode in each light-emitting diode light group transmits same data, and a visible beam of each light-emitting diode light group transmits the same data;

or

a visible beam of each light-emitting diode in each light-emitting diode light group transmits different data, and a visible beam of each light-emitting diode light group transmits the same data;

or

a visible beam of each light-emitting diode in each light-emitting diode light group transmits different data, and a visible beam of each light-emitting diode light group transmits different data.

7. A data transmission method, comprising:

performing, by a transmitter, scrambling, constellation modulation, multiple-input multiple-output precoding, and discrete Fourier transform processing sequentially on uplink user data to obtain a discrete Fourier transform symbol sequence;

performing, by the transmitter, single-carrier frequency division multiple access resource mapping on the discrete Fourier transform symbol sequence to obtain frequency domain data of a single-carrier frequency division multiple access symbol;

performing, by the transmitter, conjugate symmetric extension and inverse fast Fourier transform on the frequency domain data of the single-carrier frequency division multiple access symbol to obtain a time domain real-number sequence;

performing, by the transmitter, cyclic prefix insertion processing on the time domain real-number sequence to form a first uplink time domain baseband signal;

loading, by the transmitter, the first uplink time domain baseband signal onto a direct current of a light-emitting diode lighting circuit to form a light-emitting diode driving electrical signal; and

converting, by the transmitter, the light-emitting diode driving electrical signal into a visible beam of the light-emitting diode for transmission.

8. The data transmission method according to claim 7, further comprising:

receiving, by the transmitter, a first upper-layer scheduling command before performing the conjugate symmetric extension on the frequency domain data of the single-carrier frequency division multiple access symbol, wherein the first upper-layer scheduling command is used to instruct the transmitter to use a visible light communication mode to transmit data.

9. The data transmission method according to claim 8, when the transmitter receives a second upper-layer scheduling command, wherein the second upper-layer scheduling command is used to instruct the transmitter to use a radio frequency communication mode to transmit data, after the transmitter obtains the frequency domain data of the single-carrier frequency division multiple access symbol, the method further comprising:

performing the inverse fast Fourier transform and the cyclic prefix insertion processing on the frequency domain data of the single-carrier frequency division multiple access symbol to form a second uplink time domain baseband signal, and transmitting the second uplink time domain baseband signal through a radio frequency.

10. The data transmission method according to claim 7, further comprising:

receiving, by a receiver, the visible beam of the light-emitting diode and performing optical-to-electrical conversion to obtain the first uplink time domain baseband signal;

performing, by the receiver, cyclic prefix removal, fast Fourier transform, and conjugate symmetry removal processing on the obtained first uplink time domain baseband signal to obtain the frequency domain data of the single-carrier frequency division multiple access symbol; and

performing, by the receiver, single-carrier frequency division multiple access resource demapping, inverse discrete Fourier transform, multiple-input multiple-output detection, channel equalization, constellation demodulation, and descrambling processing sequentially on the obtained frequency domain data of the single-carrier frequency division multiple access symbol to obtain the uplink user data.

11. A transmitter, comprising:

a first processing unit, configured to perform scrambling, constellation modulation, and multiple-input multiple-output precoding processing sequentially on downlink user data to obtain a precoded symbol sequence;

a second processing unit, configured to perform time-frequency resource mapping on the precoded symbol sequence obtained by the first processing unit, to obtain frequency domain data of an orthogonal frequency division multiplexing symbol;

a third processing unit, configured to perform conjugate symmetric extension on the frequency domain data of the orthogonal frequency division multiplexing symbol, wherein the frequency domain data of the orthogonal frequency division multiplexing symbol is obtained by the second processing unit;

a fourth processing unit, configured to perform inverse fast Fourier transform on the frequency domain data obtained after the conjugate symmetric extension is performed by the third processing unit, to obtain a time domain real-number sequence;

a fifth processing unit, configured to perform cyclic prefix insertion processing on the time domain real-number sequence obtained by the fourth processing unit, to form a first downlink time domain baseband signal;

a sixth processing unit, configured to load the first downlink time domain baseband signal onto a direct current of a light-emitting diode lighting circuit to form a light-emitting diode driving electrical signal; and

a seventh processing unit, configured to convert the light-emitting diode driving electrical signal into a visible beam of the light-emitting diode for transmission.

12. The transmitter according to claim 11, further comprising:

an eighth processing unit, configured to;

before the third processing unit performs the conjugate symmetric extension on the frequency domain data of the orthogonal frequency division multiplexing symbol, wherein the frequency domain data of the orthogonal frequency division multiplexing symbol is obtained by the second processing unit, receive a first upper-layer scheduling command, wherein the first upper-layer scheduling command is used to instruct the transmitter to use a visible light communication mode to transmit data; and

notify the third processing unit of performing the conjugate symmetric extension on the frequency domain data of the orthogonal frequency division multiplexing symbol, wherein the frequency domain data of the orthogonal frequency division multiplexing symbol is obtained by the second processing unit.

13. The transmitter according to claim 12, wherein:

the eighth processing unit is further configured to;

when receiving a second upper-layer scheduling command, wherein the second upper-layer scheduling command is used to instruct the transmitter to use a radio frequency communication mode to transmit data, notify the fourth processing unit of performing inverse fast Fourier transform on the frequency domain data of the orthogonal frequency division multiplexing symbol, wherein the frequency domain data of the orthogonal frequency division multiplexing symbol is obtained by the second processing unit;

the fourth processing unit is further configured to;

according to a notification of the eighth processing unit, perform the inverse fast Fourier transform on the frequency domain data of the orthogonal frequency division multiplexing symbol, wherein the frequency domain data of the orthogonal frequency division multiplexing symbol is obtained by the second processing unit, to obtain a time domain complex sequence; and

output the time domain complex sequence to the fifth processing unit; and

the fifth processing unit is further configured to perform the cyclic prefix insertion processing on the time domain complex sequence obtained by the fourth processing unit, to form a second downlink time domain baseband signal; and

transmit the second downlink time domain baseband signal through a radio frequency.

14. The transmitter according to claim 11, wherein:

the sixth processing unit is further configured to perform amplification and pre-distortion processing on the first downlink time domain baseband signal before loading the first downlink time domain baseband signal onto the direct current of the light-emitting diode lighting circuit.

15. The transmitter according to claim 11, wherein:

the light-emitting diode is located in any one light-emitting diode light group that is formed by at least two light-emitting diodes, wherein a visible beam of each light-emitting diode in each light-emitting diode light group transmits same data, and a visible beam of each light-emitting diode light group transmits the same data;

or

a visible beam of each light-emitting diode in each light-emitting diode light group transmits different data, and a visible beam of each light-emitting diode light group transmits same data;

or

a visible beam of each light-emitting diode in each light-emitting diode light group transmits different data, and a visible beam of each light-emitting diode light group transmits different data.

16. A transmitter, comprising:

a first processing module, configured to perform scrambling, constellation modulation, multiple-input multiple-output precoding, and discrete Fourier transform processing sequentially on uplink user data to obtain a discrete Fourier transform symbol sequence;

a second processing module, configured to perform single-carrier frequency division multiple access resource mapping on the discrete Fourier transform symbol sequence obtained by the first processing module, to obtain frequency domain data of a single-carrier frequency division multiple access symbol;

a third processing module, configured to perform conjugate symmetric extension on the frequency domain data of the single-carrier frequency division multiple access symbol, wherein the frequency domain data of the single-carrier frequency division multiple access symbol is obtained by the second processing module;

a fourth processing module, configured to perform inverse fast Fourier transform on the frequency domain data obtained after the conjugate symmetric extension is performed by the third processing module, to obtain a time domain real-number sequence;

a fifth processing module, configured to perform cyclic prefix insertion processing on the time domain real-number sequence obtained by the fourth processing module, to form a first uplink time domain baseband signal;

a sixth processing module, configured to load the first uplink time domain baseband signal onto a direct current of a light-emitting diode lighting circuit to form a light-emitting diode driving electrical signal; and

a seventh processing module, configured to convert the light-emitting diode driving electrical signal into a visible beam of the light-emitting diode for transmission.

17. The transmitter according to claim 16, further comprising:

an eighth processing module, configured to;

before the third processing module performs the conjugate symmetric extension on the frequency domain data of the single-carrier frequency division multiple access symbol, wherein the frequency domain data of the single-carrier frequency division multiple access symbol is obtained by the second processing module, receive a first upper-layer scheduling command, wherein the first upper-layer scheduling command is used to instruct the transmitter to use a visible light communication mode to transmit data; and

notify the third processing module of performing the conjugate symmetric extension on the frequency domain data of the single-carrier frequency division multiple access symbol, wherein the frequency domain data of the single-carrier frequency division multiple access symbol is obtained by the second processing module.

18. The transmitter according to claim 17, wherein:

the eighth processing module is further configured to;

when receiving a second upper-layer scheduling command, wherein the second upper-layer scheduling command is used to instruct the transmitter to use a radio frequency communication mode to transmit data, notify the fourth processing module of performing the inverse fast Fourier transform on the frequency domain data of the single-carrier frequency division multiple access symbol, wherein the frequency domain data of the single-carrier frequency division multiple access symbol is obtained by the second processing module;

the fourth processing module is further configured to;

according to a notification of the eighth processing module, perform the inverse fast Fourier transform on the frequency domain data of the single-carrier frequency division multiple access symbol, wherein the frequency domain data of the single-carrier frequency division multiple access symbol is obtained by the second processing module, to obtain a time domain complex sequence; and

output the time domain complex sequence to the fifth processing module; and

the fifth processing module is further configured to perform the cyclic prefix insertion processing on the time domain complex sequence obtained by the fourth processing module, to form a second uplink time domain baseband signal, and transmit the second uplink time domain baseband signal through a radio frequency.