Method and apparatus for channel state feedback using arithmetic coding

• US 20050265436A1
• Filed: 05/31/2005
• Published: 12/01/2005
• Est. Priority Date: 06/01/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd., Winlab Rutgers University
• Original Assignee: Samsung Electronics Co. Ltd., Winlab Rutgers University
• Inventors: Park, Dong-Seek, Cho, Young-Kwon, Razoumov, Leonid, Suh, Chang-Ho, Yoon, Seok-Hyun, Raychaudhuri, Dipankar
• Granted Patent: US 7,746,802 B2
• Time in Patent Office: Days
• US Class Current: 375/221
• CPC Class Codes: H04B 7/0658 Feedback reduction
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0073 Special arrangements for feedback channel
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems

Abstract

Disclosed are the design and implementation of a CSI feedback channel in a multi-carrier wireless communication system. An apparatus and a method for channel state feedback using arithmetic coding are provided to ensure efficiency and reliability of a system by transmitting the CSI while compressing the CSI with a predetermined compression rate selected depending on a channel state. The apparatus for CSI feedback in a wireless communication system performing channel estimation at a transmitter or a receiver by using a communication channel includes a transmitter terminal transmitting a signal for CSI measurement by using the communication channel, and a receiver terminal receiving the signal from the transmitter terminal, checking a channel state based on the received signal, and transmitting the signal to the transmitter terminal after compressing the signal according to the channel state.

Claims

1. An apparatus for channel state information (CSI) feedback in a wireless communication system performing channel estimation at a transmitter or a receiver by using a communication channel, the apparatus comprising:

a transmitter terminal transmitting a signal for CSI measurement by using the communication channel; and

a receiver terminal receiving the signal from the transmitter terminal, checking a channel state based on the received signal, and transmitting the signal to the transmitter terminal after compressing the signal according to the channel state.

2. The apparatus of claim 1, wherein the communication channel is one of a pilot channel and a traffic channel.

3. The apparatus of claim 1, wherein the transmitter terminal transmits data to the receiver terminal using a traffic channel and transmits information for CSI measurement using a pilot channel.

4. The apparatus of claim 1, wherein the receiver terminal decodes data transmitted thereto from the transmitter terminal, measures an instantaneous value of the CSI by using a pilot channel, compresses CSI data into CSI feedback channel frames, and sends the CSI feedback channel frames back to the transmitter terminal.

5. The apparatus of claim 1, wherein the receiver terminal includes a receiver for receiving a pilot channel and a traffic channel from the transmitter terminal, a CSI measurement unit for measuring a CSI value by using the pilot channel, and a CSI encoder for encoding reception data and compressing CSI data into CSI feedback channel frames.

6. The apparatus of claim 5, wherein the CSI encoder includes a channel measurement unit for measuring the CSI from an input signal, a channel gain quantizer for quantizing each channel gain based on the CSI value measured by the channel measurement unit, a multiplexer for multiplexing an output of the channel gain quantizer, an arithmetic encoder for compressing the CSI using arithmetic coding, a frame section for converting compressed CSI data into CSI feedback channel frames, and a selector for selecting a CSI feedback channel frame having a predetermined compression rate corresponding to a channel state from among the CSI feedback channel frames.

7. The apparatus of claim 6, wherein the channel gain quantizer maps each channel gain measured by the channel measurement unit corresponding to a finite set.

8. The apparatus of claim 6, wherein the multiplexer takes an input stream of each sub-carrier channel gain quantized by the channel gain quantizer, multiplexes the input stream so as to transmit streams to the arithmetic encoder, and produces N identical streams in parallel which are offered as an input to N arithmetic encoders.

9. The apparatus of claim 6, wherein the arithmetic encoder performs data stream compression based upon a channel model thereof and CSI feedback channel frames.

10. The apparatus of claim 6, wherein the selector selects a shortest frame from among frames having different lengths and sends the frame over on the feedback channel.

11. The apparatus of claim 6, wherein outputs of all encoders in the wireless communication system matching with a best input CSI sequence represent best compression performance.

12. The apparatus of claim 6, wherein the CSI encoder is made of a filter bank including N arithmetic encoders.

13. The apparatus of claim 6, wherein all encoders in the wireless communication system are aligned in parallel to each other, and an encoder which produces a shortest encoded sequence is selected.

14. The apparatus of claim 6, wherein the feedback channel frame includes a preamble and a frame body, the preamble has at least two fields including an Idx field having compression rate information and a length field having compression rate check information and the frame body includes a payload field having compressed feedback information and a cyclic redundancy check field for checking an occurrence of error.

15. The apparatus of claim 1, wherein the transmitter terminal includes a transmitter for transmitting the pilot channel and the traffic channel, and a CSI decoder for receiving and decoding a CSI feedback channel transmitted thereto from the receiver terminal.

16. The apparatus of claim 15, wherein the CSI decoder includes at least one arithmetic decoder corresponding to a filter bank of a CSI encoder, and only one arithmetic decoder operates corresponding to the filter bank of the transmitter terminal in order to decode CSI gains.

17. A method to feedback channel state information (CSI) in a wireless communication system performing channel estimation at a transmitter or a receiver by using a communication channel, the method comprising the steps of:

transmitting a data signal for CSI measurement by using the communication channel; and

receiving the data signal from a transmitter terminal, checking a channel state based on the received data signal, and transmitting the data signal to the transmitter terminal after compressing the data signal according to the channel state.

18. The method of claim 17, wherein the communication channel is one of a pilot channel and a traffic channel.

19. The method of claim 17, wherein data are transmitted using a traffic channel and information for CSI measurement is transmitted using a pilot channel.

20. The method of claim 17, wherein the data transmitted from the transmitter terminal are decoded, an instantaneous value of the CSI is measured by using a pilot channel, and CSI data are transmitted back to the transmitter terminal after being compressed into CSI feedback channel frames.

21. The method of claim 17, wherein compressing the data signal includes:

receiving a pilot channel and a traffic channel from the transmitter terminal and measuring a CSI value by using the pilot channel; and

encoding reception data and compressing CSI data into CSI feedback channel frames.

22. The method of claim 21, wherein compressing the CSI data includes:

measuring the CSI from an input signal and quantizing each channel gain based on the CSI value measured by a channel measurement unit;

multiplexing quantized channel gains and compressing the CSI using arithmetic coding;

converting compressed CSI data into CSI feedback channel frames; and

selecting a CSI feedback channel frame having a predetermined compression rate corresponding to a channel state from among the compressed CSI feedback channel frames.

23. The method of claim 22, wherein a channel gain quantizer maps each channel gain measured by the channel measurement unit corresponding to a finite alphabet.

24. The method of claim 22, wherein a multiplexer multiplexes an input stream of each quantized sub-carrier channel gain and transmits streams to an arithmetic encoder by producing N identical streams in parallel which are offered as an input to N arithmetic encoders.

25. The method of claim 22, wherein data stream compression is performed based upon a channel model and feedback channel frames.

26. The method of claim 22, wherein a shortest frame is selected from among frames having different lengths and the frame is sent over a feedback channel.

27. The method of claim 22, wherein outputs of all encoders of the wireless communication system matching with a best input CSI sequence represent best compression performance.

28. The method of claim 22, wherein all encoders of the wireless communication system are aligned in parallel to each other, and an encoder which produces a shortest encoded sequence is selected.