Apparatus and method for encoding/decoding transport format combination indicator in CDMA mobile communication system

• US 20050083901A1
• Filed: 12/07/2004
• Published: 04/21/2005
• Est. Priority Date: 07/06/1999
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kang, Hee-Won, Kim, Jae-Yoel
• Granted Patent: US 7,706,348 B2
• Time in Patent Office: Days
• US Class Current: 370/342
• CPC Class Codes: H03M 13/136 Reed-Muller [RM] codes
• CPC Class Codes: H03M 13/47 Error detection, forward error correction or error protection, not provided for in groups H03M13/01 - H03M13/37
• CPC Class Codes: H03M 13/618 Shortening and extension of codes
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 2201/70705 Rate detection
• CPC Class Codes: H04J 13/0048 Walsh
• CPC Class Codes: H04J 13/12 Generation of orthogonal codes
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0028 Formatting
• CPC Class Codes: H04L 1/0039 other detection of signalling, e.g. detection of TFCI explicit signalling H04L1/0046, H04L27/0012 and H04L25/0262 take precedence
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data

Abstract

An apparatus and method for encoding/decoding a transport format combination indicator (TFCI) in a CDMA mobile communication system. In the TFCI encoding apparatus, a one-bit generator generates a sequence having the same symbols. A basis orthogonal sequence generator generates a plurality of basis orthogonal sequences. A basis mask sequence generator generates a plurality of basis mask sequences. An operation unit receives TFCI bits that are divided into a first information part representing biorthogonal sequence conversion, a second information part representing orthogonal sequence conversion, and a third information part representing mask sequence conversion and combines an orthogonal sequence selected from the basis orthogonal sequence based on the second information, a biorthogonal sequence obtained by combining the selected orthogonal sequence with the same symbols selected based on the first information part, and a mask sequence selected based on the biorthogonal sequence and the third information part, thereby generating a TFCI sequence.

Claims

1. A TFCI encoding apparatus in a CDMA mobile communication system, comprising:

an orthogonal sequence generator for generating a plurality of basis biorthogonal sequences;

a mask sequence generator for generating a plurality of basis mask sequences; and

an operation unit for adding a basis biorthogonal sequence and a basis mask sequence selected among the basis biorthogonal sequences and the basis mask sequences according to TFCI bits.

2. The TFCI encoding apparatus of claim 1, wherein the plurality of basis biorthogonal sequences are a first Walsh code, a second Walsh code, a fourth Walsh code, an eighth Walsh code, a sixteenth Walsh code and an all “

1”

sequence which converts the orthogonal sequences to the biorthogonal sequences.

3. The TFCI encoding apparatus of claim 2, wherein the plurality of biorthogonal sequences are Walsh codes and bi-orthogonal complement sequences of the Walsh codes.

4. The TFCI encoding apparatus of claim 1, wherein the mask sequence generator has a first m-sequence and a second m-sequence which can be added together to form a Gold code, forms a first sequence group having sequences formed by cyclically shifting the first m-sequence and a second sequence group having sequences formed by cyclically shifting the second m-sequence, generates and applies a column transposition function to the sequences in the first group to convert the sequences in the first group to orthogonal sequences, inserts a column of ‘

0’

in the front of the sequences in the second group, and generates and applies a reverse column transposition function to the sequences in the second group to convert the sequences in the second group to mask sequences.

5. The TFCI encoding apparatus of claim 1, wherein the basis mask sequences are a first mask sequence “

00101000011000111111000001110111”

, a second mask sequence “

00000001110011010110110111000111”

, a fourth mask sequence “

00001010111110010001101100101011”

, and an eighth mask sequence “

00011100001101110010111101010001”

.

6. The TFCI encoding apparatus of claim 1, wherein the operation unit comprises:

a plurality of first multipliers for multiplying the basis biorthogonal sequences by corresponding TFCI bits;

a plurality of second multipliers for multiplying the basis mask sequences by corresponding TFCI bits; and

an adder for adding the outputs of the first and second multipliers and generating the sum as the TFCI sequence.

7. The TFCI encoding apparatus of claim 6, wherein the same symbols are Is.

8. The TFCI encoding apparatus of claim 6, wherein the plurality of basis orthogonal sequences are a first Walsh code, a second Walsh code, a fourth Walsh code, an eighth Walsh code, and a sixteenth Walsh code.

9. An apparatus for encoding TFCI bits including first information bits and second information bits in a CDMA mobile communication system, comprising:

an orthogonal sequence generator for generating a plurality of biorthogonal sequences and outputting a biorthogonal sequence selected based on the first information bits among the plurality of biorthogonal sequences;

a mask sequence generator for generating a plurality of mask sequences and outputting a mask sequence selected based on the second information bits among the plurality of mask sequences; and

an adder for adding the biorthogonal sequence and the mask sequence received from the orthogonal sequence generator.

10. The TFCI encoding apparatus of claim 9, wherein the mask sequence generator has a first m-sequence and a second m-sequence which can be added together to form a Gold code, forms a first sequence group having sequences formed by cyclically shifting the first m-sequence and a second sequence group having sequences formed by cyclically shifting the second m-sequence, generates and applies a column transposition function to the sequences in the first group to convert the sequences in the first group to orthogonal sequences, inserts a column of ‘

0’

in the front of the sequences in the second group, and generates and applies a reverse column transposition function to the sequences in the second group to convert the sequences in the second group to the mask sequences.

11. A TFCI encoding method in a CDMA mobile communication system, comprising the steps of:

generating a plurality of basis biorthogonal sequences;

generating a plurality of basis mask sequences; and

adding a basis biorthogonal sequence and a basis mask sequence selected among the basis biorthogonal sequences and the basis mask sequences according to TFCI bits.

12. The TFCI encoding method of claim 11, wherein the plurality of basis biorthogonal sequences are a first Walsh code, a second Walsh code, a fourth Walsh code, an eighth Walsh code, a sixteenth Walsh code and an all “

1”

sequence which converts the orthogonal sequences to the biorthogonal sequences.

13. The TFCI encoding apparatus of claim 11, wherein the mask sequence generator has a first m-sequence and a second m-sequence which can be added together to form a Gold code, forms a first sequence group having sequences formed by cyclically shifting the first m-sequence and a second sequence group having sequences formed by cyclically shifting the second m-sequence, generates and applies a column transposition function to the sequences in the first group to convert the sequences in the first group to orthogonal sequences, inserts a column of ‘

0’

in the front of the sequences in the second group, and generates and applies a reverse column transposition function to the sequences in the second group to convert the sequences in the second group to the mask sequences.

14. The TFCI encoding method of claim 11, wherein the basis mask sequences are a first mask sequence “

00101000011000111111000001110111”

, a second mask sequence “

00000001110011010110110111000111”

, a fourth mask sequence “

00001010111110010001101100101011”

, and an eighth mask sequence “

00011100001101110010111101010001”

.

15. The TFCI encoding method of claim 11, wherein the basis orthogonal sequences are multiplied by corresponding TFCI bits, the basis mask sequences are multiplied by corresponding TFCI bits, and the multiplication results are added to the TFCI sequence in the TFCI sequence generating step.

16. A method of encoding TFCI bits including first information bits and second information bits in a CDMA mobile communication system, comprising the steps of:

generating a plurality of biorthogonal sequences and outputting a biorthogonal sequence selected based on the first information bits among the plurality of biorthogonal sequences;

generating a plurality of mask sequences and outputting a mask sequence selected based on the second information bits among the plurality of mask sequences; and

adding the selected biorthogonal sequence and the selected mask sequence.

17. The TFCI encoding method of claim 16, wherein the plurality of biorthogonal sequences are Walsh codes and complement codes of the Walsh codes.

18. The TFCI encoding apparatus of claim 16, wherein the mask sequence generator has a first m-sequence and a second m-sequence which can be added together to form a Gold code, forms a first sequence group having sequences formed by cyclically shifting the first m-sequence and a second sequence group having sequences formed by cyclically shifting the second m-sequence, generates and applies a column transposition function to the sequences in the first group to convert the sequences in the first group to orthogonal sequences, inserts a column of ‘

0’

in the front of the sequences in the second group, and generates and applies a reverse column transposition function to the sequences in the second group to convert the sequences in the second group to the mask sequences.

19. A TFCI encoding method in a CDMA mobile communication system, comprising the steps of:

generating the same symbols;

generating a plurality of basis orthogonal sequences;

generating a plurality of basis mask sequences;

receiving TFCI bits and multiplying the same symbols by corresponding TFCI bits, the plurality of basis orthogonal sequences by corresponding TFCI bits, and the plurality of basis mask sequences by corresponding TFCI bits; and

adding the multiplication results.

20. The TFCI encoding method of claim 19, wherein the same symbols are Is.

21. The TFCI encoding method of claim 19, wherein the plurality of basis orthogonal sequences are a first Walsh code, a second Walsh code, a fourth Walsh code, an eighth Walsh code, and a sixteenth Walsh code.

22. The TFCI encoding apparatus of claim 19, wherein the mask sequence generator has a first m-sequence and a second m-sequence which can be added together to form a Gold code, forms a first sequence group having sequences formed by cyclically shifting the first m-sequence and a second sequence group having sequences formed by cyclically shifting the second m-sequence, generates and applies a column transposition function to the sequences in the first group to convert the sequences in the first group to the orthogonal sequences, inserts a column of ‘

0’

in the front of the sequences in the second group, and generates and applies a reverse column transposition function to the sequences in the second group to convert the sequences in the second group to the mask sequences.

23. The TFCI encoding method of claim 19, wherein the basis mask sequences are a first mask sequence “

00101000011000111111000001110111”

, a second mask sequence “

00000001110011010110110111000111”

, a fourth mask sequence “

00001010111110010001101100101011”

, and an eighth mask sequence “

00011100001101110010111101010001”

.

24. A TFCI decoding apparatus in a CDMA mobile communication system, comprising:

a mask sequence generator for generating at least one mask sequence;

at least one operation circuit for receiving an input signal and the generated mask sequence and removing the mask sequences from the input signal by multiplying the mask sequence by the input signal; and

at least one correlator for receiving the signal from the operation circuit, calculating correlation values of the received signal with a plurality of orthogonal sequences numbered with corresponding indexes, and selecting the largest of the calculated correlation value and the orthogonal sequence index corresponding to the largest correlation value.

25. The TFCI encoding apparatus of claim 24, wherein the mask sequence generator has a first m-sequence and a second m-sequence which can be added together to form a Gold code, forms a first sequence group having sequences formed by cyclically shifting the first m-sequence and a second sequence group having sequences formed by cyclically shifting the second m-sequence, generates and applies a column transposition function to the sequences in the first group to convert the sequences in the first group to orthogonal sequences, inserts a column of ‘

0’

in the front of the sequences in the second group, and generates and applies a reverse column transposition function to the sequences in the second group to convert the sequences in the second group to the mask sequences.

26. The TFCI decoding apparatus of claim 24, wherein the operation circuit is a multiplier.

27. The TFCI decoding apparatus of claim 24, further comprising a correlation comparator for determining the largest correlation value received from a plurality of correlators and generating an orthogonal sequence index and a mask sequence index corresponding to the largest correlation value.

28. The TFCI decoding apparatus of claim 27, wherein the mask sequence index is the index of the mask sequence used to remove a mask sequence from the input signal.

38. The TFCI decoding method of claim 26, wherein the mask sequence index is the index of the mask sequence used to remove a mask sequence from the input signal corresponding to the highest correlation value.

29. A TFCI decoding method in a CDMA mobile communication system, comprising the steps of:

generating at least one mask sequence;

receiving an input signal and the mask sequence and removing a mask sequence from the input signal by multiplying the mask sequence by the input signal;

receiving the product signal, calculating correlation values of the product signal with a plurality of orthogonal sequences having corresponding indexes; and

selecting the largest correlation value from the calculated correlation values and outputting an orthogonal sequence index corresponding to the largest correlation value.

30. The TFCI encoding apparatus of claim 29, wherein the mask sequence generator has a first m-sequence and a second m-sequence which can be added together to form a Gold code, forms a first sequence group having sequences formed by cyclically shifting the first m-sequence and a second sequence group having sequences formed by cyclically shifting the second m-sequence, generates and applies a column transposition function to the sequences in the first group to convert the sequences in the first group to orthogonal sequences, inserts a column of ‘

0’

in the front of the sequences in the second group, and generates and applies a reverse column transposition function to the sequences in the second group to convert the sequences in the second group to the mask sequences.

31. The TFCI decoding method of claim 29, further comprising the step of determining the highest correlation value from the selected largest correlation values obtained by selecting the largest correlation value from the calculated correlation values;

and outputting an orthogonal sequence index and a mask sequence index corresponding to the determined highest correlation value.

32. The TFCI decoding apparatus of claim 31, wherein the mask sequence index is the index of the mask sequence used to remove a mask sequence from the input signal corresponding to the highest correlation value.

33. A TFCI decoding method in a CDMA mobile communication system, comprising the steps of:

generating a plurality of mask sequences;

receiving an input signal and the mask sequences and removing a mask sequence from the input signal by multiplying the mask sequences by the input signal;

receiving the product signals, calculating correlation values of each of the product signals with a plurality of orthogonal sequences having corresponding indexes, and selecting the largest correlation values and orthogonal sequence indexes corresponding to the largest correlation values; and

determining the highest correlation value from the largest correlation values and outputting an orthogonal sequence index and a mask sequence index corresponding to the determined highest correlation value.

34. The TFCI encoding apparatus of claim 33, wherein the mask sequence generator has a first m-sequence and a second m-sequence which can be added together to form a Gold code, forms a first sequence group having sequences formed by cyclically shifting the first m-sequence and a second sequence group having sequences formed by cyclically shifting the second m-sequence, generates and applies a column transposition function to the sequences in the first group to convert the sequences in the first group to orthogonal sequences, inserts a column of ‘

0’

in the front of the sequences in the second group, and generates and applies a reverse column transposition function to the sequences in the second group to convert the sequences in the second group to the mask sequences.

35. The TFCI decoding method of claim 33, wherein the mask sequence index is the index of the mask sequence used to remove a mask sequence from the input signal corresponding to the highest correlation value.

36. A TFCI decoding method in a CDMA mobile communication system, comprising the steps of:

generating a plurality of mask sequences;

receiving an input signal and the mask sequences and multiplying each mask sequence by the input signal;

receiving the multiplied signals and calculating correlation values of each of the received multiplied signals with a plurality of orthogonal sequences having corresponding indexes;

selecting the largest correlation value among the calculated correlation values for each of the multiplied signals and an orthogonal sequence index corresponding to the largest correlation value; and

;

determining the highest correlation value from all of the largest correlation values and an orthogonal code index corresponding to the highest correlation value.

37. The TFCI encoding apparatus of claim 36, wherein the mask sequence generator has a first m-sequence and a second m-sequence which can be added together to form a Gold code, forms a first sequence group having sequences formed by cyclically shifting the first m-sequence and a second sequence group having sequences formed by cyclically shifting the second m-sequence, generates and applies a column transposition function to the sequences in the first group to convert the sequences in the first group to orthogonal sequences, inserts a column of ‘

0’

in the front of the sequences in the second group, and generates and applies a reverse column transposition function to the sequences in the second group to convert the sequences in the second group to the mask sequences.