Method of determining a variable quantization step size for improving channel decoding, method and apparatus of performing channel decoding operation based on a variable quantization step size

1. A method of determining a variable quantization step size for maximizing the performance of a channel decoder, the method comprising:

receiving a frame from a channel;

obtaining a channel characteristic parameter in order to calculate a quantization step size (Δ) used in channel decoding; and

determining the quantization step size (Δ) variably based on the channel characteristic parameter,

wherein the channel characteristic parameter includes an average channel estimation value (a CH ) generated based on a channel estimation of the frame, a signal-to-noise ratio (SNR) parameter (a SNR ) obtained based on the SNR of the frame, a modulation parameter (a MOD ) set according to a receiver system, and a multiple-input multiple-output (MIMO) parameter (a MIMO ) set according to the receiver system.

2. The method of claim 1 , further comprising:

generating a quantization table based on the calculated quantization step size (Δ).

3. The method of claim 1 , wherein the frame corresponds to a forward error correction (FEC) block used in either one of orthogonal frequency division multiplexing (OFDM) and orthogonal frequency division multiple access (OFDMA).

4. The method of claim 1 , wherein obtaining the channel characteristic parameter comprises:

calculating the average channel estimation value (a CH ) generated based on the channel estimation of the frame;

obtaining the SNR parameter (a SNR ) based on the SNR of the frame; and

obtaining the modulation parameter (a MOD ) set according to the receiver system and the MIMO parameter (a MIMO ) set according to the receiver system.

5. The method of claim 1 , wherein the quantization step size (Δ) satisfies the following equation:

( a CH ·a MOD ·a MIMO +a SNR )/2 q−1 ,

where q corresponds to the number of quantization bits.

6. A method of performing channel decoding based on a variable quantization step size, the method comprising:

receiving a frame from a channel;

obtaining a channel characteristic parameter in order to calculate a quantization step size (Δ) used in the channel decoding;

determining the quantization step size (Δ) variably based on the channel characteristic parameter; and

determining the number of bits inputted to the channel decoding based on the calculated quantization step size (Δ),

wherein the channel characteristic parameter includes an average channel estimation value (a CH ) generated based on a channel estimation of the frame, an SNR parameter (a SNR ) obtained based on the SNR of the frame, a modulation parameter (a MOD ) set according to a receiver system and a multiple-input multiple-output MIMO parameter (a MIMO ) set according to the receiver system.

7. The method of claim 6 , further comprising:

generating a quantization table based on the calculated quantization step size (Δ).

8. The method of claim 6 , wherein the frame corresponds to an FEC block used in either one of OFDM and OFDMA.

9. The method of claim 6 , wherein obtaining the channel characteristic parameter comprises:

calculating the average channel estimation value (a CH ) generated based on the channel estimation of the frame;

obtaining the SNR parameter (a SNR ) based on the SNR of the frame; and

obtaining the modulation parameter (a MOD ) set according to the receiver system and the MIMO parameter (a MIMO ) set according to the receiver system.

10. The method of claim 6 , wherein the quantization step size (Δ) satisfies the following equation:

( a CH ·a MOD ·a MIMO +a SNR )/2 q −1,

where q corresponds to the number of quantization bits.

11. The method of claim 10 , wherein the number (CD INPUT ) of bits inputted to the channel decoding equals C, C satisfies TH C−1 <LLR<TH C , and TH C satisfies the following equation:

TH

C

=

{

-

∞

for

⁢

⁢

C

=

-

1

(

C

+

1

-

2

q

-

1

)

⁢

Δ

for

⁢

⁢

C

=

0

,

1

,

…

⁢

,

2

q

-

2

∞

for

⁢

⁢

C

=

-

2

q

-

1

where CD INPUT corresponds to the number of bits inputted to the channel decoding, C corresponds to a constant, LLR corresponds to a calculation result of a log-likelihood ratio (LLR), and q corresponds to the number of quantization bits.

12. A receiving apparatus, comprising:

a quantization table generation unit configured to obtain a channel characteristic parameter in order to calculate a quantization step size (Δ) used in channel decoding and variably determine a quantization step size (Δ) based on the channel characteristic parameter; and

a quantization unit configured to determine a number of bits inputted to the channel decoding based on the determined quantization step size (Δ),

wherein the channel characteristic parameter includes an average channel estimation value (a CH ) generated based on a channel estimation of the frame, an SNR parameter (a SNR ) obtained based on the SNR of the frame, a modulation parameter (a MOD ) set according to a receiver system, and a multiple-input multiple-output (MIMO) parameter (a MIMO ) set according to the receiver system.

13. The apparatus of claim 12 , wherein quantization table generation unit generates a quantization table based on the calculated quantization step size (Δ).

14. The apparatus of claim 12 , wherein the frame corresponds to an FEC block used in either one of OFDM and OFDMA.

15. The apparatus of claim 12 , wherein the quantization step size (Δ) satisfies the following equation:

( a CH ·a MOD ·a MIMO +a SNR )/2 q−1 ,

where q corresponds to the number of quantization bits.

16. The apparatus of claim 15 , wherein the number (CD INPUT ) of bits inputted to the channel decoding equals C, C satisfies TH C−1 <LLR<TH C , and TH C satisfies the following equation:

TH

C

=

{

-

∞

for

⁢

⁢

C

=

-

1

(

C

+

1

-

2

q

-

1

)

⁢

Δ

for

⁢

⁢

C

=

0

,

1

,

…

⁢

,

2

q

-

2

∞

for

⁢

⁢

C

=

-

2

q

-

1

where CD INPUT corresponds to the number of bits inputted to the channel decoding, C corresponds to a constant, LLR corresponds to a calculation result of an LLR, and q corresponds to the number of quantization bits.

17. The apparatus of claim 12 , further comprising:

a channel decoder configured to perform the channel decoding based on the determined number of bits inputted to the channel decoding.