Transmission method using scalable video coding and mobile communication system using same

• US 20080064425A1
• Filed: 05/10/2007
• Published: 03/13/2008
• Est. Priority Date: 09/11/2006
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Hwang, Seong-Taek, Choi, Do-In, Oh, Yun-Je, Kim, Sung-Kee, Kim, Yong-Gyoo
• Application Number:
  US11/801,731
• Publication Number:
  US 20080064425A1
• Time in Patent Office: Days
• US Class Current: 455/466
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04N 19/164 Feedback from the receiver or from the transmission channel
• CPC Class Codes: H04N 19/187 the unit being a scalable video layer
• CPC Class Codes: H04N 19/67 involving unequal error protection [UEP], i.e. providing protection according to the importance of the data
• CPC Class Codes: H04N 21/234327 by decomposing into layers, e.g. base layer and one or more enhancement layers
• CPC Class Codes: H04N 21/234363 by altering the spatial resolution, e.g. for clients with a lower screen resolution
• CPC Class Codes: H04N 21/234381 by altering the temporal resolution, e.g. decreasing the frame rate by frame skipping
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/2402 Monitoring of the downstream path of the transmission network, e.g. bandwidth available traffic monitoring in data switching networks H04L43/00; monitoring data switching networks utilization H04L43/0876
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities
• CPC Class Codes: H04N 21/6405 Multicasting data broadcast and multicast in packet switching networks H04L12/18
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services

Abstract

A mobile communication system for providing a multicast/broadcast service is disclosed. The mobile communication systems comprise a base station that encodes video data of the mobile communication system into scalable bit streams and adaptively modulates and channel codes the scalable bit streams. A mobile communication terminal receives, demodulates and channel decodes the scalable bit streams transmitted from the base station and performs a process for scalable decoding the bit streams according to reception sensitivity. Overall system efficiency can be improved while increasing a transmission rate using scalable video coding according to channel characteristics between the mobile communication terminal and the base station in the multicast/broadcast service. Quality of service (QoS) can be provided based on the performance of the mobile communication terminal.

Claims

1. A mobile communication system for providing at least one of multicast and broadcast services, comprising:

a base station for encoding video data of the mobile communication system into scalable bit streams and adaptively modulating and channel coding the scalable bit streams; and

a mobile communication terminal for receiving, demodulating and channel decoding the scalable bit streams transmitted from the base station and performing a process for scalable decoding the bit streams according to reception sensitivity.

2. The mobile communication system of claim 1, wherein the base station comprises:

a scalable video coding (SVC) encoder for encoding the video data into the scalable bit streams according to channel characteristics;

a buffer for receiving and storing the scalable bit streams;

a modulator for performing multiple adaptive modulation and channel-coding processes for the stored scalable bit streams;

a radio frequency (RF) module for transmitting and receiving adaptively modulated and channel-coded bit streams; and

a channel quality information (CQI) processor for measuring a signal to noise ratio (SNR) of each channel of the mobile communication system on a basis of a radio signal received from the RF module and operating an adaptive modulation and coding scheme.

3. The mobile communication system of claim 2, wherein the SVC encoder encodes the video data according to channel characteristics based on the SNR of each channel measured by the CQI processor.

4. The mobile communication system of claim 2, wherein the scalable bit streams are encoded in a multilayer scalable video coding scheme in accordance with at least one scalability method selected from the group consisting of:

spatial scalability, SNR scalability and temporal scalability.

5. The mobile communication system of claim 2, wherein the buffer prevents the bit streams from being output when load occurs on the base station.

6. The mobile communication system of claim 2, wherein the CQI processor controls priorities of the scalable bit streams.

7. The mobile communication system of claim 6, wherein the CQI processor controls modulation and coding rates of the bit streams according to channel characteristics based on the SNR.

8. The mobile communication system of claim 2, wherein the modulator first modulates and channel codes a bit stream with a priority using a modulation scheme of a high modulation rate and a low coding rate.

9. The mobile communication system of claim 8, wherein the modulation scheme is selected from the group consisting of:

quadrature phase shift keying (QPSK), 16-quadrature amplitude modulation (16QAM) and 64-quadrature amplitude modulation (64QAM).

10. The mobile communication system of claim 1, wherein the mobile communication terminal comprises:

a radio frequency (RF) module for receiving at least one bit stream transmitted from the base station;

a demodulator for demodulating and channel decoding the received bit streams;

an extractor for measuring reception sensitivity of the demodulated and channel-decoded bit streams and determining whether scalable video coding (SVC) decoding is possible;

an SVC decoder for scalable decoding the channel-decoded bit streams; and

a display for reproducing the scalable decoded bit streams.

11. The mobile communication system of claim 10, wherein the extractor outputs a bits stream to the SVC decoder when the bit stream is a base layer and measures reception sensitivity of a channel of the bit stream transmitted from the base station when the bit stream is not the base layer.

12. The mobile communication system of claim 11, wherein the extractor determines whether decoding is possible by checking performance related to at least one of a screen size and processor power of the mobile communication terminal according to the reception sensitivity of the channel.

13. The mobile communication system of claim 10, wherein the SVC decoder performs a process for decoding the received bit streams when the performance of the mobile communication terminal is good and decodes only a bit stream capable of being received when the performance of the mobile communication terminal is bad.

14. A transmission method using scalable video coding in a mobile communication system for providing at least one of multicast and broadcast services, comprising:

measuring, by a base station, channel characteristics based on a signal to noise ratio (SNR) of a received signal on each channel of the mobile communication system comprises the steps of;

encoding video data of the mobile communication system into scalable bit streams according to the channel characteristics;

storing the scalable bit streams;

determining modulation and coding rates of the scalable bit streams;

modulating and channel coding the scalable bit streams at the determined modulation and coding rates; and

transmitting the modulated and channel-coded bit streams to a mobile communication terminal.

15. The transmission method of claim 14, wherein the step of encoding comprises the step of:

performing an encoding process by selecting at least one modulation scheme selected from the group consisting of;

spatial scalability, SNR scalability and temporal scalability.

16. The transmission method of claim 14, wherein the step of controlling comprises the step of:

controlling priorities of the scalable bit streams.

17. The transmission method of claim 14, wherein the step of modulating and channel coding comprise the step of:

first modulating and channel coding a bit stream with a priority using a modulation scheme of a high modulation rate and a low coding rate.

18. A mobile communication method using scalable video coding in a mobile communication system for providing at least one of multicast and broadcast services, comprising:

receiving, by a mobile communication terminal, bit streams transmitted from a base station of the mobile communication system;

demodulating and channel decoding the bit streams;

determining whether an demodulated and channel decoded bit stream is a base layer;

measuring reception sensitivity of the bit stream upon determining that the demodulated and channel-decoded bit stream is not the base layer;

checking performance of the mobile communication terminal when the measured reception sensitivity of the bit stream is more than a preset reference value and determining whether scalable decoding is possible;

decoding at least one of the remaining bit streams when the performance of the mobile communication terminal is good and decoding only a bit stream capable of being received when the performance of the mobile communication terminal is bad; and

reproducing decoded scalable bit streams.

19. The mobile communication method of claim 18, further comprising the step of:

scalable decoding the bit stream upon determining that the demodulated and channel-decoded bit stream is the base layer.

20. The mobile communication method of claim 18, further comprising the step of:

discarding the demodulated and channel-decoded bit stream when the measured reception sensitivity of the bit stream is less than the preset reference value.

21. A base station for encoding video data of a mobile communication system into scalable bit streams comprising:

a scalable video coding (SVC) encoder for encoding the video data into the scalable bit streams;

a buffer for receiving and storing the scalable bit streams;

a modulator for performing multiple modulation and channel-coding processes for the stored scalable bit streams, wherein said bit streams are modulated with a progressive lower modulation and progress higher coding rate;

a radio frequency (RF) module for transmitting the modulated and channel-coded bit streams; and

a channel quality information (CQI) processor for measuring a signal to noise ratio (SNR) of each channel of the mobile communication system on a basis of a radio signal received from the RF module.

22. The base station of claim 21, wherein the SVC encoder encodes the video data according to channel characteristics based on the SNR of each channel measured by the CQI processor.

23. The base station of claim 21, wherein the scalable bit streams are encoded in a multilayer scalable video coding scheme in accordance with at least one scalability method selected from the group consisting of:

spatial scalability, SNR scalability and temporal scalability.

24. The base station of claim 21, wherein the CQI processor controls modulation and coding rates of the bit streams according to a least one channel characteristic.

25. The base station of claim 24, wherein the at least one channel characteristic is a SNR.

26. The base station of claim 21, wherein the modulator first modulates and channel codes a bit stream with a priority using a modulation scheme of a high modulation rate and a low coding rate.

27. The base station of claim 26, wherein the modulation scheme of a bit stream selected as being higher than that of a prior bit stream and the coding rate of the bit stream is selected as being lower than that of the prior bit stream.

28. The base station of claim 21, wherein each bit stream is determined as a difference with a prior bit stream.