WLAN transmitter having high data throughput

• US 20050186986A1
• Filed: 05/28/2004
• Published: 08/25/2005
• Est. Priority Date: 02/19/2004
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Shen, Ba-Zhong, Hansen, Christopher J., Tran, Hau Thien, Trachewsky, Jason A., Cameron, Kelly Brian, Seshadri, Nambirajan
• Granted Patent: US 8,059,740 B2
• Time in Patent Office: Days
• US Class Current: 455/553.100
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/0065 Serial concatenated codes
• CPC Class Codes: H04L 1/0066 Parallel concatenated codes
• CPC Class Codes: H04L 1/0068 by puncturing
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/0618 Space-time coding
• CPC Class Codes: H04L 25/03866 using scrambling
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points

Abstract

A wireless local area network (WLAN) transmitter includes a baseband processing module and a plurality of radio frequency (RF) transmitters. The baseband processing module is operably coupled to process data by scrambling the data in accordance with a pseudo random sequence to produce scrambled data. The processing of the data continues by selecting one of a plurality of encoding modes based on a mode selection signal. The processing of the data continues by encoding the scrambled data in accordance with the one of the plurality of encoding modes to produce encoded data. The processing of the data continues by determining a number of transmit streams based on the mode selection signal. The processing of the data further continues by converting the encoded data into streams of symbols in accordance with the number of transmit streams and the mode selection signal. A number of the plurality of RF transmitters are enabled based on the mode selection signal to convert a corresponding one of the streams of symbols into a corresponding RF signal such that a corresponding number of RF signals is produced.

Claims

1. A wireless local area network (WLAN) transmitter having high data throughput, the WLAN transmitter comprises:

a baseband processing module operably coupled to;

receive data and a mode selection signal;

scramble the data in accordance with a pseudo random sequence to produce scrambled data;

select one of a plurality of encoding modes based on the mode selection signal;

encode the scrambled data in accordance with the one of the plurality of encoding modes to produce encoded data;

determine a number of transmit streams based on the mode selection signal; and

convert the encoded data into streams of symbols in accordance with the number of transmit streams and the mode selection signal; and

a plurality of radio frequency (RF) transmitters, wherein, based on the mode selection signal, a number of the plurality of RF transmitters are enabled, wherein each of the number of plurality of RF transmitters that are enabled converts a corresponding one of the streams of symbols into a corresponding RF signal such that a corresponding number of RF signals is produced.

2. The WLAN transmitter of claim 1, wherein the converting the encoded data further comprises:

interleaving the encoded data over multiple symbols and subcarriers of a channel to produce interleaved data;

demultiplexing the interleaved data into a number of parallel streams of interleaved data, wherein the number of parallel streams corresponds to the number of transmit streams;

for each of the parallel streams of interleaved data;

mapping the interleaved data into a quadrature amplitude modulated (QAM) symbol to produce frequency domain symbols;

converting the frequency domain symbols into time domain symbols; and

space and time encoding the time domain symbols of each of the parallel streams of interleaved data to produce the streams of symbols.

3. The WLAN transmitter of claim 2, wherein the space and time encoding comprises at least one of:

space and time encoding the time domain symbols of one of the parallel streams of interleaved data into one of the streams of symbols utilizing an encoding matrix; and

space and time encoding the time domain symbols of M parallel streams of the interleaved data into P streams of symbols using the encoding matrix, where P=M+1.

4. The WLAN transmitter of claim 3, wherein the encoding matrix comprises a form of:

$\hspace{1em}<br><br>\left[\begin{array}{ccccc}{C}_1& C_2& C_3& \mathrm{\dots <br><br>}& C_{2<br><br>M-1}\\ -C_2^{*}& C_1^{*}& C_4& \mathrm{\dots <br><br>}& C_{2<br><br>M}\end{array}\right]$

where a number of rows of the encoding matrix corresponds to M and a number of columns of the encoding matrix corresponds to P.

5. The WLAN transmitter of claim 2, wherein the QAM symbols comprises at least one of:

Binary Phase Shift Keying (BPSK);

Quadrature Phase Shift Keying (QPSK);

Complimentary Code Keying (CCK);

16 QAM;

64 QAM; and

256 QAM.

6. The WLAN transmitter of claim 1, wherein the mode selection signal comprises an indication for one or more of the following modes:

frequency band of 2.4 GHz, channel bandwidth of 20-22 MHz, and a maximum bit rate of 54 Mega bits per second (Mbps);

frequency band of 5 GHz, channel bandwidth of 20 MHz, and a maximum bit rate of 54 Mbps;

frequency band of 2.4 GHz, channel bandwidth of 20 MHz, and a maximum bit rate of 192 Mbps;

frequency band of 5 GHz, channel bandwidth of 20 MHz, and a maximum bit rate of 192 Mbps; and

frequency band of 5 GHz, channel bandwidth of 40 MHz, and a maximum bit rate of 486 Mbps.

7. The WLAN of claim 1, wherein each of the plurality of RF transmitters comprises:

a digital filter and upsampling module operably coupled to filter and upsample the corresponding one of the streams of symbols into filtered symbols;

a digital to analog conversion module operably coupled to convert the filtered symbols into analog signals;

analog filter operably coupled to filter the analog signals to produce filtered analog signals;

up-conversion module operably coupled to convert the filtered analog signals into high frequency signals based on a local oscillation;

power amplifier operably coupled to amplify the high frequency signals to produce amplified high frequency signals; and

RF filter operably coupled to filter the amplified RF signals to produce the corresponding RF signal.

8. The WLAN of claim 1 further comprises:

a mode manager module operably coupled to determine the mode selection signal based on WLAN operational conditions, which include protocol diversity of wireless communication devices affiliated with a corresponding WLAN, target capabilities, and WLAN transmitter capabilities.

9. The WLAN transmitter of claim 1, wherein the encoding of the scrambled data in accordance with the one of the plurality of encoding modes comprises:

performing a convolutional encoding with sixty-four state codes and generator polynomials g₀=133₈ and g₁=171₈ on the scrambled data to produce convolutional encoded data;

puncturing the convolution encoded data at one of a plurality of rates in accordance with the mode selection signal to produce the encoded data.

10. The WLAN transmitter of claim 9, wherein the performing the convolutional encoding further comprises:

combining the convolutional encoding with an outer Reed-Solomon code to produce the convolutional encoded data.

11. The WLAN transmitter of claim 1, wherein the encoding of the scrambled data in accordance with the one of the plurality of encoding modes comprises:

encoding the scrambled data in accordance with a complimentary code keying (CCK) code to produce the encoded data.

12. The WLAN transmitter of claim 11, wherein the encoding further comprises:

combining the CCK code with an outer Reed-Solomon code to produce the encoded data.

13. The WLAN transmitter of claim 1, wherein the encoding of the scrambled data in accordance with the one of the plurality of encoding modes comprises:

performing a convolutional encoding with two hundred fifty-six state codes and generator polynomials g₀=561₈ and g₁=753₈ on the scrambled data to produce convolutional encoded data; and

puncturing the convolution encoded data at one of a plurality of rates in accordance with the mode selection signal.

14. The WLAN transmitter of claim 13, wherein the performing the convolutional encoding further comprises:

combining the convolutional encoding with an outer Reed-Solomon code to produce the convolutional encoded data.

15. The WLAN transmitter of claim 1, wherein the encoding of the scrambled data in accordance with the one of the plurality of encoding modes comprises at least one of:

a parallel concatenated turbo encoding scheme; and

a low density parity check (LDPC) block encoding scheme.

16. A wireless local area network (WLAN) transmitter having high data throughput, the WLAN transmitter comprises:

a scramble module operably coupled to scramble data in accordance with a pseudo random sequence to produce scrambled data;

an encoding module operably coupled to encode the scrambled data in accordance with one of a plurality of encoding modes to produce encoded data, wherein the one of the plurality of encoding modes is selected in accordance with a mode selection signal;

an interleaving module operably coupled to interleave the encoded data in accordance with the mode selection signal to produce interleaved data;

a demultiplexing module operably coupled to convert the interleaved data into one or more streams of interleaved data based on the mode selection signal;

a plurality of symbol mapping modules, wherein each of one or more of the plurality of symbol mapping modules is active to map, in accordance with the mode selection signal, the interleaved data of a corresponding stream of the one or more streams of interleaved data into a mapped symbols, wherein the one or more of the plurality of symbol mapping modules produces one or more streams of mapped symbols;

a plurality of frequency domain to time domain conversion modules, wherein each of one or more of the plurality of frequency domain to time domain conversion modules converts a corresponding stream of the one or more streams of mapped symbols into time domain symbols, wherein the one or more of the plurality of frequency domain to time domain conversion modules produce one or more streams of time domain symbols;

a space and time encoding module operably coupled to convert the one or more streams of time domain symbols into one or more streams of spatially adjusted time domain symbols; and

a plurality of radio frequency (RF) transmitters, wherein one or more of the RF transmitters is active, based on the mode selection signal, to convert the one or more streams of spatially adjusted time domain symbols into one or more RF signals.

17. The WLAN transmitter of claim 16, wherein the space and time encoding module further functions to:

space and time encoding the one or more streams of time domain symbols into the one or more streams of spatially adjusted time domain symbols utilizing an encoding matrix;

or

space and time encoding the time domain symbols of M parallel streams of the time domain symbols into P streams of the spatially adjusted time domain symbols using the encoding matrix, where P=M+1.

18. The WLAN transmitter of claim 17, wherein the encoding matrix comprises a form of:

$\hspace{1em}<br><br>\left[\begin{array}{ccccc}{C}_1& C_2& C_3& \mathrm{\dots <br><br>}& C_{2<br><br>M-1}\\ -C_2^{*}& C_1^{*}& C_4& \mathrm{\dots <br><br>}& C_{2<br><br>M}\end{array}\right]$

where a number of rows of the encoding matrix corresponds to M and a number of columns of the encoding matrix corresponds to P.

19. The WLAN transmitter of claim 16, wherein each of the plurality of symbol mapping modules, when active, maps the interleaved data to quadrature amplitude modulation (QAM) frequency domain symbols that comprises at least one of:

Binary Phase Shift Keying (BPSK);

Quadrature Phase Shift Keying (QPSK);

Complimentary Code Keying (CCK);

16 QAM;

64 QAM; and

256 QAM.

20. The WLAN transmitter of claim 16, wherein the mode selection signal comprises an indication for one or more of the following modes:

frequency band of 2.4 GHz, channel bandwidth of 20-22 MHz, and a maximum bit rate of 54 Mega bits per second (Mbps);

frequency band of 5 GHz, channel bandwidth of 20 MHz, and a maximum bit rate of 54 Mbps;

frequency band of 2.4 GHz, channel bandwidth of 20 MHz, and a maximum bit rate of 192 Mbps;

frequency band of 5 GHz, channel bandwidth of 20 MHz, and a maximum bit rate of 192 Mbps; and

frequency band of 5 GHz, channel bandwidth of 40 MHz, and a maximum bit rate of 486 Mbps.

21. The WLAN transmitter of claim 19, wherein each of the plurality of RF transmitters comprises:

a digital filter and upsampling module operably coupled to filter and upsample the streams of spatially adjusted time domain symbols into filtered symbols;

a digital to analog conversion module operably coupled to convert the filtered symbols into analog signals;

analog filter operably coupled to filter the analog signals to produce filtered analog signals;

up-conversion module operably coupled to convert the filtered analog signals into RF signals based on a local oscillation;

power amplifier operably coupled to amplify the RF signals to produce amplified RF signals; and

RF filter operably coupled to filter the amplified RF signals to produce the corresponding RF signals.

22. The WLAN transmitter of claim 16 further comprises:

a mode manager module operably coupled to determine the mode selection signal based on WLAN operational conditions, which include protocol diversity of wireless communication devices affiliated with a corresponding WLAN, target capabilities, and WLAN transmitter capabilities.

23. The WLAN transmitter of claim 16, wherein the encoding module operably coupled to encodes the scrambled data in accordance with the one of the plurality of encoding modes by:

performing a convolutional encoding with sixty-four state codes and generator polynomials g₀=133₈ and g₁=171₈ on the scrambled data to produce convolutional encoded data;

puncturing the convolution encoded data at one of a plurality of rates in accordance with the mode selection signal to produce the encoded data.

24. The WLAN transmitter of claim 23, wherein the performing the convolutional encoding further comprises:

combining the rate ½

convolutional encoding with an outer Reed-Solomon code to produce the convolutional encoded data.

25. The WLAN transmitter of claim 16, wherein the encoding module operably coupled to encodes the scrambled data in accordance with the one of the plurality of encoding modes by:

encoding the scrambled data in accordance with a complimentary code keying (CCK) code to produce the encoded data.

26. The WLAN transmitter of claim 25, wherein the encoding further comprises:

combining the CCK code with an outer Reed-Solomon code to produce the encoded data.

27. The WLAN transmitter of claim 16, wherein the encoding module operably coupled to encodes the scrambled data in accordance with the one of the plurality of encoding modes by:

performing a convolutional encoding with two hundred fifty-six state codes and generator polynomials g₀=561₈ and g₁=753₈ on the scrambled data to produce convolutional encoded data; and

puncturing the convolution encoded data at one of a plurality of rates in accordance with the mode selection signal.

28. The WLAN transmitter of claim 27, wherein the performing the convolutional encoding further comprises:

combining the convolutional encoding with an outer Reed-Solomon code to produce the convolutional encoded data.

29. The WLAN transmitter of claim 16, wherein the encoding module operably coupled to encodes the scrambled data in accordance with the one of the plurality of encoding modes by at least one of:

a parallel concatenated turbo encoding scheme; and

a low density parity check (LDPC) block encoding scheme.