Apparatus and method for scrambling control field information for wireless communications

• US 9,832,058 B2
• Filed: 11/01/2016
• Issued: 11/28/2017
• Est. Priority Date: 11/03/2015
• Status: Active Grant

• Current Assignee: Atlas Global Technologies LLC (Acacia Research Corporation)
• Original Assignee: Newracom Inc.
• Inventors: Lee, Dae Won, Noh, Yujin, Kwon, Young Hoon, Seok, Yongho, Moon, Sungho
• Primary Examiner(s): Mian, Omer S
• Application Number:
  US15/340,939
• Publication Number:
  US 20170126456A1
• Time in Patent Office: 392 Days
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data
• CPC Class Codes: H04L 25/03866 using scrambling
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2621 Reduction thereof using phase offsets between subcarriers
• CPC Class Codes: H04L 27/2627 Modulators
• CPC Class Codes: H04L 27/2634 Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

In wireless communications, a high-efficiency (HE) physical layer protocol data unit (PPDU) includes an HE signal-B (SIG-B) field. In order to prevent undesirably large peak-to-average power ratio (PAPR) transmissions caused by repeated information in the HE SIG-B field, the HE SIG-B field may be scrambled. Scrambling of the HE SIG-B field may include scrambling of modulated data tones of each of one or more HE SIG-B field channels of the HE SIG-B field. This scrambling may include applying a phase rotation to the modulated data tones within each of the one or more HE SIG-B field channels. This scrambling (or phase rotation) is performed in addition to a phase rotation applied to each entire HE SIG-B field channel that is commonly referred to as a gamma rotation.

Claims

1. A wireless device for transmitting a frame, comprising:

one or more memories; and

one or more processors coupled to the one or more memories, the one or more processors configured to cause;

generating a high-efficiency (HE) physical layer protocol data unit (PPDU) including an HE signal B (HE-SIG-B) field that immediately follows an HE signal A (HE-SIG- A) field and immediately precedes an HE short training field (HE-STF), wherein the generating comprises;

generating coded HE-SIG-B bits, interleaving the coded HE-SIG-B bits to generate interleaved HE-SIG-B bits, modulating the interleaved HE-SIG-B bits to generate N modulated symbols, N being a positive integer, generating N phase-rotated symbols by applying a first set of N phase rotation values to the N modulated symbols respectively, and by applying a second set of N phase rotation values to the N modulated symbols respectively, wherein the second set of N phase rotation values is different from the first set of N phase rotation values, and

transforming the N phase-rotated symbols to an orthogonal frequency-division multiplexing (OFDM) symbol of the HE-SIG-B field; and

transmitting the HE PPDU;

wherein the coded HE-SIG-B bits belong to a 20 MHz HE-SIG-B unit of the HE-SIG-B field,

wherein at least two complex values in the first set of N phase rotation values scrambling sequence are different resulting in different phase rotations, and each phase rotation value in the second set of N phase rotation values has the same value corresponding to the 20 MHz HE-SIG-B unit to each of the modulated symbols.

2. The wireless device of claim 1, wherein:

the transmitting comprises transmitting the HE PPDU in 40 MHz, when the 20 MHz HE-SIG-B unit has a first frequency band, the same value is equal to +1, and

when the 20 MHz HE-SIG-B unit has a second frequency band higher than the first frequency band, the same value is equal to +j, wherein j is the imaginary unit which satisfies the equation j²=−

1.

3. The wireless device of claim 1, wherein:

the transmitting comprises transmitting the HE PPDU in 80 MHz, when the 20 MHz HE-SIG-B unit has a first frequency band, the same value is equal to +1,

when the 20 MHz HE-SIG-B unit has a second frequency band higher than the first frequency band, the same value is equal to −

1,

when the 20 MHz HE-SIG-B unit has a third frequency band higher than the second frequency band, the same value is equal to −

1, and

when the 20 MHz HE-SIG-B unit has a fourth frequency band higher than the third frequency band, the same value is equal to −

1.

4. The wireless device of claim 1, wherein the first set of N phase rotation values is for reducing peak-to-average power ratio (PAPR) occurring within the 20 MHz HE-SIG-B unit of the HE-SIG-B field, and wherein the second set of N phase rotation values is for reducing PAPR occurring between at least two 20 MHz HE-SIG-B units of the HE-SIG-B field.

5. The wireless device of claim 1, wherein the HE PPDU further comprises i) a non-high throughput (HT) short training field (L-STF), a non-HT long training field (L-LTF), a non-HT signal (L-SIG) field, a repeated L-SIG field, and the HE signal A (HE-SIG-A) field which are followed by the HE-SIG-B field, and ii) the HE-STF, an HE-LTF, and an HE-data field which follow the HE-SIG-B field.

6. The wireless device of claim 1, wherein generating the coded HE-SIG-B bits comprises:

binary convolutional code (BCC) encoding HE-SIG-B bits to generate BCC-encoded HE-SIG-B bits, and

puncturing the BCC-encoded HE-SIG-B bits to generate the coded HE-SIG-B bits.

7. A wireless device for receiving a frame, comprising:

one or more memories; and

one or more processors coupled to the one or more memories, the one or more processors configured to cause;

receiving a high-efficiency (HE) physical layer protocol data unit (PPDU) including an HE signal B (HE-SIG-B) field that immediately follows an HE signal A (HE-SIG- A) field and immediately precedes an HE short training field (HE-STF);

transforming an orthogonal frequency-division multiplexing (OFDM) symbol of the HE-SIG-B field to N phase-rotated symbols, N being a positive integer;

generating N modulated symbols by applying a first set of N phase rotation values to the N phase-rotated symbols respectively, and by applying a second set of N phase rotation values to the N phase-rotated symbols respectively, wherein the second set of N phase rotation

values is different from the first set of N phase rotation values;

demodulating the N modulated symbols to generate interleaved HE-SIG-B bits;

de-interleaving the interleaved HE-SIG-B bits to generate coded HE-SIG-B bits;

and decoding the coded HE-SIG-B bits to obtain HE-SIG-B bits;

wherein the coded HE-SIG-B bits belong to a 20 MHz HE-SIG-B unit of the HE-SIG-B field,

wherein at least two complex values in the first set of N phase rotation values scrambling sequence are different resulting in different phase rotations, and each phase rotation value in the second set of N phase rotation values has the same value corresponding to the 20 MHz HE-SIG-B unit to each of the modulated symbols.

8. The wireless device of claim 7, wherein the HE-SIG-B bits belong to a 20 MHz HE-SIG-B unit of the HE-SIG-B field.

9. The wireless device of claim 7, wherein the HE PPDU further comprises i) a non-high throughput (HT) short training field (L-STF), a non-HT long training field (L-LTF), a non-HT signal (L-SIG) field, a repeated L-SIG field, and the HE signal A (HE-SIG-A) field which are followed by the HE-SIG-B field, and ii) the HE-STF, an HE-LTF, and an HE-data field which follow the HE-SIG-B field.

10. The wireless device of claim 7, wherein decoding the coded HE-SIG- B bits comprises:

de-puncturing the coded HE-SIG-B bits to generate the de-punctured HE-SIG-B bits, and

binary convolutional code (BCC) decoding the de-punctured HE-SIG-B bits to generate the HE-SIG-B bits.

11. A method for a wireless device to transmit a frame, the method comprising:

generating a high-efficiency (HE) physical layer protocol data unit (PPDU) including an HE signal B (HE-SIG-B) field that immediately follows an HE signal A (HE-SIG-A) field and immediately precedes an HE short training field (HE-STF), wherein the generating comprises;

generating coded HE-SIG-B bits, interleaving the coded HE-SIG-B bits to generate interleaved HE-SIG-B bits, modulating the interleaved HE-SIG-B bits to generate N modulated symbols, N being a positive integer, generating N phase-rotated symbols by applying both a first set of N phase rotation valuespattern and a second phase rotation pattern to the N modulated symbols respectively, and by applying a second set of N phase rotation values to the N modulated symbols respectively, wherein the second set of N phase rotation values is different from the first set of N phase rotation values, and

transforming the N phase-rotated symbols to an orthogonal frequency-division multiplexing (OFDM) symbol of the HE-SIG-B field; and

transmitting the HE PPDU;

wherein the coded HE-SIG-B bits belong to a 20 MHz HE-SIG-B unit of the HE-SIG-B field,

wherein at least two complex values in the first set of N phase rotation values scrambling sequence are different resulting in different phase rotations, and each phase rotation value in the second set of N phase rotation values has the same value corresponding to the 20 MHz HE-SIG-B unit to each of the modulated symbols.