Granted Patent B2

US 9,413,576 · App. 14/834,117 · Granted Aug 9, 2016

Inventors: Sudhir Srinivasa (Campbell, CA); Hongyuan Zhang (Fremont, CA); Rohit U. Nabar (Sunnyvale, CA)

Assignee: Marvell World Trade Ltd.

H04L27/2608H04L1/0016H04W84/12

Abstract

Claims (68)

1. A method, comprising:

selecting, at a communication device, a number of spatial streams N SS ;

selecting, at the communication device, a channel bandwidth;

selecting, at the communication device, a modulation coding scheme (MCS) from i) a first set of MCSs when the selected channel bandwidth is a first channel bandwidth, or ii) a second set of MCSs when the selected channel bandwidth is a second channel bandwidth, wherein

the first set of MCSs is different than the second set of MCSs, and

the second set of MCSs excludes MCSs from the first set of MCSs that will result in a padding-related constraint not being met when the second channel bandwidth is to be used;

encoding, at the communication device, information bits according to the selected MCS;

after encoding, parsing, at the communication device, the information bits into N SS spatial streams;

after parsing, interleaving, at the communication device, the information bits in each spatial stream, including

entering the information bits into a matrix having an integer number of rows equal to N ROW and an integer number of columns equal to N COL ,

reading the information bits out from the matrix in the N COL columns, and

applying a frequency rotation r according to

r =( j−f*N ROT N BPSCS ( i SS ))mod N CBPSS ( i SS )

where i SS is a spatial stream index from 1, 2, . . . N SS , N CBPSS (i SS ) is a number of coded bits per symbol for an i SS th spatial stream, N BPSCS (i SS ) is a number of coded bits per carrier for the i SS th spatial stream, j=0, 1, . . . , N CBPSS (i SS )−1, f is an integer that varies based on the spatial stream index i SS , and N ROT is an interleaving parameter;

after interleaving, modulating, at the communication device, the information bits according to the selected MCS; and

generating, at the communication device, a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols using the modulated information bits.

2. The method of claim 1 , wherein the first set of MCSs excludes MCSs from the second set of MCSs that will result in a padding-related constraint not being met when the first channel bandwidth is to be used.

3. The method of claim 1 , wherein the second channel bandwidth is 80 MHz.

4. The method of claim 3 , wherein:

the first set of MCSs includes an MCS corresponding to 64-quadrature amplitude modulation £64-QAM modulation) and rate 3/4 encoding; and

the second set of MCSs excludes the MCS corresponding to 64-QAM modulation and rate 3/4 encoding.

5. The method of claim 3 , wherein, when the second channel bandwidth is selected, generating the plurality of OFDM symbols comprises:

generating OFDM symbols corresponding to a 256-point inverse discrete Fourier transform (256 IDFT) and with pilot tones at four subcarrier index pairs chosen from a set of pairs consisting of {±11, ±25, ±39, ±53, ±75, ±89, ±103, ±117.

6. The method of claim 5 , wherein, when the second channel bandwidth is selected, generating the plurality of OFDM symbols comprises:

generating OFDM symbols with

guard tones only at subcarrier indices i) −128 to −123 and ii)+123 to +127, and

direct current (DC) tones only at subcarrier indices −1 to +1.

7. The method of claim 1 , wherein N ROW *N COL =N Tone *N BPSCS (i SS ) holds for all i SS , where N Tone is a number of data tones, and where N BPSCS (i SS ) is a number of coded bits per subcarrier for the i SS th spatial stream.

8. The method of claim 1 , wherein N ROT =(N Tone /N SS )+C, where N Tone is a number of data tones, and where C is either zero or a non-zero integer constant.

9. The method of claim 1 , wherein:

encoding information bits includes encoding the information bits to generate binary convolutional code (BCC) encoded data using one or more BCC encoders.

10. The method of claim 1 , further comprising:

selecting, at the communication device, the parameter N ROW using the selected MCS, wherein N ROW is the same for some MCSs.

11. A communication device, comprising:

a network interface device having one or more integrated circuit devices, the one or more integrated circuit devices including a memory to store indicators of a first set of modulation coding schemes (MCSs) and a second set of MCSs that correspond to a number of spatial streams and a number of encoders, wherein

the first set of MCSs is different than the second set of MCSs, and

the second set of MCSs excludes MCSs from the first set of MCSs that will result in a padding-related constraint not being met when a second channel bandwidth is to be used;

wherein the one or more integrated circuit devices are configured to

select a number of spatial streams N SS ,

select a channel bandwidth,

select an MCS from i) the first set of MCSs when the selected channel bandwidth is a first channel bandwidth, or ii) the second set of MCSs when the selected channel bandwidth is a second channel bandwidth,

encode information bits according to the selected MCS,

after encoding, parse the information bits into N SS spatial streams,

after parsing, interleave the information bits in each spatial stream, including

entering the information bits into a matrix having an integer number of rows equal to N ROW and an integer number of columns equal to N COL ,

reading the information bits out from the matrix in the N COL columns, and

applying a frequency rotation r according to

r =( j−f*N ROT *N BPSCS ( i SS ))mod N CBPSS ( i SS )

where i SS is a spatial stream index from 1, 2, . . . N SS , N CBPSS (i SS ) is a number of coded bits per symbol for an i SS th spatial stream, N BPSCS (i SS ) is a number of coded bits per carrier for the i SS th spatial stream, j=0, 1, . . . , N CBPSS (i SS )−1, f is an integer that varies based on the spatial stream index i SS , and N ROT is an interleaving parameter; and

wherein the one or more integrated circuit devices are further configured to

after interleaving, modulate the information bits according to the selected MCS, and

generate a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols using the modulated information bits.

12. The communication device of claim 11 , wherein the first set of MCSs excludes MCSs from the second set of MCSs that will result in a padding-related constraint not being met when the first channel bandwidth is to be used.

13. The communication device of claim 11 , wherein the second channel bandwidth is 80 MHz.

14. The communication device of claim 13 , wherein:

the first set of MCSs includes an MCS corresponding to 64-quadrature amplitude modulation (64-QAM modulation) and rate 3/4 encoding; and

the second set of MCSs excludes the MCS corresponding to 64-QAM modulation and rate 3/4 encoding.

15. The communication device of claim 13 , wherein, when the second channel bandwidth is selected, generating the plurality of OFDM symbols comprises:

generating OFDM symbols corresponding to a 256-point inverse discrete Fourier transform (256 IDFT) and with pilot tones at four subcarrier index pairs chosen from a set of pairs consisting of {±11, ±25, ±39, ±53, ±75, ±89, ±103, ±117.

16. The communication device of claim 15 , wherein the one or more integrated circuit devices are configured to, when the second channel bandwidth is selected, generate the plurality of OFDM symbols with

guard tones only at subcarrier indices i) −128 to −123 and ii)+123 to +127, and

direct current (DC) tones only at subcarrier indices −1 to +1.

17. The communication device of claim 11 , wherein N ROW *N COL =N Tone *N BPSCS (i SS ) holds for all i SS , where N Tone is a number of data tones, and where N BPSCS (i SS ) is a number of coded bits per subcarrier for the i SS th spatial stream.

18. The communication device of claim 11 , wherein N ROT =(N Tone /N SS )+C, where N Tone is a number of data tones, and where C is either zero or a non-zero integer constant.

19. The communication device of claim 11 , wherein the one or more integrated circuit devices include:

a plurality of binary convolutional code (BCC) encoders to encode the information bits according to a BCC.

20. The communication device of claim 11 , wherein the one or more integrated circuit devices are configured to:

select the parameter N ROW using the selected MCS, wherein N ROW is the same for some MCSs.

Assignments (6)

Continuity (10)