WIRELESS TRANSMISSION APPARATUS AND RELATED WIRELESS TRANSMISSION METHOD

• US 20080176509A1
• Filed: 01/22/2008
• Published: 07/24/2008
• Est. Priority Date: 01/24/2007
• Status: Active Grant

• Current Assignee: Realtek Semiconductor Corp.
• Original Assignee: Realtek Semiconductor Corp.
• Inventors: Liu, Der-Zheng, Yu, Jiun-Hung, Yen, Kuang-Yu, Chang, Chung-Yao
• Granted Patent: US 9,136,963 B2
• Time in Patent Office: Days
• US Class Current: 455/3.01
• CPC Class Codes: H04H 20/42 Arrangements for resource management
• CPC Class Codes: H04H 20/61 for local area broadcast, e.g. instore broadcast
• CPC Class Codes: H04H 60/11 Arrangements for counter-measures when a portion of broadcast information is unavailable

Abstract

A wireless transmission method for broadcasting packets to a plurality of receiving devices includes: broadcasting a plurality of packets to the receiving devices, receiving signals transmitted from the receiving devices, generating a plurality of estimation results according to the signals transmitted from the receiving devices where each of the estimation results corresponds to a receiving quality while each of the receiving devices receives the packets, determining whether each of the receiving devices is suitable for receiving the packets according to each of the estimation results and a recipient condition and storing information of at least one of the receiving devices suitable for receiving the packets, and determining whether the at least one of the receiving devices needs to receive a broadcasted packet again according to the information and signals transmitted from the at least one of the receiving devices suitable for receiving the packets.

Claims

1. A wireless transmission apparatus for broadcasting packets to a plurality of receiving devices, the wireless transmission apparatus comprising:

a transmitter, for broadcasting packets to the receiving devices;

a receiver, for receiving signals transmitted from any one of the receiving devices; and

an estimation circuit, coupled to the receiver for determining whether each of the receiving devices is suitable for receiving the packets broadcasted by the wireless transmission apparatus according to the signals transmitted from the receiving devices and a recipient condition and for determining each one of the receiving devices that is suitable for receiving the packets broadcasted by the wireless transmission apparatus as a target receiving device, the estimation circuit comprising;

a signal quality estimation circuit, for generating a plurality of estimation results according to the signals transmitted from the receiving devices, each of the estimation results corresponds to a receiving quality of each receiving device while receiving the packets broadcasted by the wireless transmission apparatus;

a control circuit, coupled to the signal quality estimation circuit, for determining whether each of the receiving devices is the target receiving device or not according to each estimation result and the recipient condition; and

a storage unit, coupled to the control circuit, for storing information of at least one of the target receiving devices;

wherein the wireless transmission apparatus determines whether at least one of the target receiving devices needs to retrieve a broadcasted packet again according to the information and the signals transmitted from the at least one of the target receiving devices and rebroadcasts the broadcasted packet again if needed.

2. The wireless transmission apparatus of claim 1, wherein the wireless transmission apparatus determines a throughput according to a predetermined mechanism or according to settings of a user through a user interface, and determines the recipient condition according to the throughput.

3. The wireless transmission apparatus of claim 2, wherein the recipient condition is a predetermined signal-to-noise ratio (SNR) and/or a packet error rate, and the signal quality estimation circuit is a signal-to-noise ratio estimation circuit and/or a packet error rate estimation circuit.

4. The wireless transmission apparatus of claim 3, wherein the signal-to-noise ratio estimation circuit comprises:

a signal intensity detector, coupled to the receiver, for detecting the intensity of the signals transmitted from the receiving devices to generate a plurality of detection results, each of the detection results corresponds to the intensity of the signals transmitted from each of the receiving devices; and

a mapping table, coupled to the signal intensity detector and to the control circuit, for generating the estimation results according to the detection results.

5. The wireless transmission apparatus of claim 3, wherein the wireless transmission apparatus transmits the packets of a plurality of particular formats to any one of the receiving devices and the receiving device transmits an acknowledge signal to the wireless transmission device every time when completing the receipt of the packets of each particular format, and the packet error ratio estimation circuit comprises:

a counter, coupled to the receiver and the control circuit, for generating one of the estimation results according to the acknowledge signal/signals.

6. The wireless transmission apparatus of claim 5, wherein the particular format is binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), 16 quadrature amplitude modulation (16 QAM), 64 quadrature amplitude (64 QAM), 128 quadrature amplitude (128 QAM) or 256 quadrature amplitude (256 QAM).

7. The wireless transmission apparatus of claim 1, wherein the control circuit determines whether each of the receiving devices is the target receiving device and stores the information of the target receiving devices by judging whether the estimation results satisfy the recipient condition.

8. The wireless transmission apparatus of claim 7, wherein the wireless transmission apparatus determines whether any one of the target devices needs to retrieve the broadcasted packet again according to the information and the signals transmitted from the target receiving devices, and rebroadcasts the broadcasted packet again if needed.

9. The wireless transmission apparatus of claim 7, wherein the control circuit selects a reference receiving device from the target receiving devices and stores the information of the reference receiving device according to differences between each of the estimation results and the recipient condition, and the wireless transmission apparatus determines whether the reference receiving device needs to retrieve the broadcasted packet again according to the information and the signals transmitted from the reference receiving device and rebroadcasts the broadcasted packet again if needed.

10. The wireless transmission apparatus of claim 9, wherein the control circuit determines whether the reference receiving device needs to retrieve the broadcasted packet again when a first condition is satisfied, and determines whether the reference receiving device and/or other target receiving devices need to retrieve the broadcasted packet again when a second condition is satisfied.

11. The wireless transmission apparatus of claim 10, wherein a period that satisfies with the first condition is smaller than a period that satisfies with the second condition.

12. The wireless transmission apparatus of claim 9, wherein the control circuit determines a consecutive transmission frequency of each packet broadcasted by the wireless transmission apparatus according to the packet error ratio of the reference receiving device.

13. The wireless transmission apparatus of claim 7, wherein the control circuit determines a retransmission priority and/or a retransmission available time of each target receiving device according to the differences between each of the estimation results and the recipient condition, and the wireless transmission apparatus rebroadcasts the broadcasted packet according to the retransmission priority and/or the retransmission available time.

14. The wireless transmission apparatus of claim 1, wherein the control circuit selects a reference receiving device from the target receiving devices and stores the information of the reference receiving device according to differences between each of the estimation results and the recipient condition, and the wireless transmission apparatus determines whether the reference receiving device needs to retrieve the broadcasted packet again according to the information and the signals transmitted from the reference receiving device and rebroadcasts the broadcasted packet again if needed.

15. The wireless transmission apparatus of claim 14, wherein the control circuit determines a consecutive transmission frequency of each packet broadcasted by the wireless transmission apparatus according to the packet error ratio of the reference receiving device.

16. The wireless transmission apparatus of claim 1 further comprising:

an encoder, for encoding initial data to generate encoded data; and

an interleaver, coupled to the encoder and to the transmitter, for interleaving the encoded data to generate encoded initial data, the transmitter broadcasts the packets according to the encoded initial data.

17. The wireless transmission apparatus of claim 1, wherein the wireless transmission apparatus utilizes a first frequency band to broadcast the packets and utilizes a second frequency band to rebroadcast the broadcasted packets, and at least one of the target receiving devices utilizes the first frequency band to receive the packets of the first frequency band and utilizes the second frequency band to receive the re-broadcasted packets.

18. The wireless transmission apparatus of claim 1, wherein the wireless transmission apparatus utilizes a first channel to broadcast the packets and utilizes a second channel to rebroadcast the broadcasted packets, and at least one of the target receiving devices utilizes the first channel to receive the packets of the first channel and utilizes the second channel to receive the re-broadcasted packets.

19. The wireless transmission apparatus of claim 1, wherein the control circuit permits the wireless transmission apparatus to communicate data with any one of the receiving devices within a scheduled period according to a predetermined time.

20. The wireless transmission apparatus of claim 1, wherein the wireless transmission device is a wireless local area network (WLAN) access point, a personal computer (PC), a personal digital assistant (PDA), a mobile, or a TV set-top box.

21. A wireless transmission method for broadcasting packets to a plurality of receiving devices, the wireless transmission method comprising:

broadcasting a plurality of packets to the receiving devices;

receiving signals transmitted from the receiving devices to generate a plurality of estimation results, each of the estimation results corresponds to recipient quality of each receiving device while receiving the packets;

determining whether each of the receiving devices is suitable for receiving the packets according to each of the estimation results and a recipient condition and determining each one of the receiving devices that is suitable for receiving the packets as a target receiving device;

storing information of at least one of the target receiving devices; and

determining whether at least one of the target receiving devices needs to retrieve a broadcasted packet again according to the information and the signals transmitted from the at least one of the target receiving devices and re-broadcasting the broadcasted packet again if needed.

22. The wireless transmission method of claim 21 further comprising:

determining a throughput according to a predetermined mechanism or according to settings of a user through a user interface, and determining the recipient condition according to the throughput.

23. The wireless transmission method of claim 22, wherein the recipient condition is a predetermined signal-to-noise ratio (SNR) and/or a packet error rate.

24. The wireless transmission method of claim 23, wherein the step of generating the estimation results comprises a signal-to-noise ratio estimating step, comprising:

detecting the intensity of the signals transmitted from the receiving devices to generate a plurality of detection results, each of the detection results corresponding to the intensity of the signals transmitted from each of the receiving devices; and

generating the estimation results according to the detection results.

25. The wireless transmission method of claim 23, wherein the step of generating the estimation results comprises a packet error rate estimating step, comprising:

transmitting the packets of a plurality of particular formats to any one of the receiving devices, and the receiving device transmitting an acknowledge signal every time when completing the receipt of the packets of each particular format;

receiving the acknowledge signals; and

counting the acknowledge signals to generate one of the estimation results.

26. The wireless transmission method of claim 21, wherein the step of determining whether at least one of the target receiving devices needs to retrieve the broadcasted packet comprises:

selecting a reference receiving device from the target receiving devices and storing the information of the reference receiving device according to differences between each of the estimation results and the recipient condition; and

determining whether the reference receiving device needs to retrieve the broadcasted packet again according to the information and the signals transmitted from the reference receiving device and re-broadcasting the broadcasted packet again if needed.

27. The wireless transmission method of claim 26 further comprising:

determining a consecutive transmission frequency of each of the packets according to

the packet error ratio of the reference receiving device.

28. The wireless transmission method of claim 21, wherein the step of broadcasting the packets to the receiving devices comprises:

encoding initial data to generate encoded data;

interleaving the encoded data to generate encoded initial data;

generating the packets according to the encoded initial data; and

broadcasting the packets.

29. The wireless transmission method of claim 21, wherein the step of broadcasting the packets to the receiving devices comprises:

utilizing a first frequency band to broadcast the packets and utilizing a second frequency band to rebroadcast the broadcasted packets; and

at least one of the target receiving devices utilizing the first frequency band to receive the packets and utilizing the second frequency band to receive the re-broadcasted packets.

30. The wireless transmission method of claim 21, wherein the step of broadcasting the packets to the receiving devices comprises:

utilizing a first channel to broadcast the packets and utilizing a second channel to rebroadcast the broadcasted packets; and

at least one of the target receiving devices utilizing the first channel to receive the packets and utilizing the second channel to receive the re-broadcasted packets.