Transmission of wide bandwidth signals in a network having legacy devices

• US 20050190724A1
• Filed: 10/26/2004
• Published: 09/01/2005
• Est. Priority Date: 02/13/2004
• Status: Active Grant

• Current Assignee: Broadcom Corporation (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Moorti, R. Tushar, Hansen, Christopher J., Trachewsky, Jason A.
• Granted Patent: US 7,400,643 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A method for transmitting wide bandwidth signals in a network that includes legacy devices begins by determining channel bandwidth of a channel that supports the wide bandwidth signals in the network. The method continues by determining overlap of legacy channel bandwidth with the channel bandwidth of the channel. The method continues by providing a legacy readable preamble section within the channel where the legacy channel bandwidth overlaps the channel bandwidth of the channel.

Claims

1. A method for transmitting wide bandwidth signals in a network that includes legacy devices, the method comprises:

determining channel bandwidth of a channel that supports the wide bandwidth signals in the network;

determining overlap of legacy channel bandwidth with the channel bandwidth of the channel; and

providing a legacy readable preamble section within the channel where the legacy channel bandwidth overlaps the channel bandwidth of the channel.

2. The method of claim 1 further comprises:

utilizing at least a portion of payload spectrum of the channel that for packet header transmission, wherein the packet header transmission includes at least a portion of the legacy readable preamble.

3. The method of claim 2, wherein the utilizing the at least a portion of the payload spectrum comprises at least one of:

utilizing a same power spectral density for the packet header transmission and for the payload; and

utilizing a different power spectral density for the packet header transmission and for the payload.

4. The method of claim 1 further comprises:

interpreting, by the legacy devices, the legacy readable preamble such that the legacy devices appropriately defer transmissions and decode a portion of the wide bandwidth signals within a channel spectrum of the legacy devices.

5. The method of claim 1 further comprises:

generating a wide-bandwidth preamble of the wide bandwidth signals for at least one of;

Carrier detection;

Gain control;

Frequency offset estimation;

Channel estimation;

Transmission Deference; and

Data demodulation.

6. A method for generating a preamble of a frame for a wide-bandwidth channel wireless communication, the method comprises:

generating a legacy carrier detect field;

generating a channel sounding field, wherein the channel sounding field includes a plurality of tones within the wide-bandwidth channel, wherein a first set of the plurality of tones corresponds to tones of a legacy channel sounding field; and

generating a legacy signal field, wherein, in time, the legacy signal field follows the channel sounding field, which follows the legacy carrier detect field.

7. The method of claim 6 further comprises:

generating at least one additional channel sounding field that includes a second plurality of tones; and

generating another signal field, wherein the at least one additional channel sounding field follows, in time, the legacy signal field, and the another signal field follows the at least one additional channel sounding field.

8. The method of claim 6 comprises:

generating the legacy carrier detect field in accordance with a legacy wireless protocol, wherein a legacy channel of the legacy wireless protocol has a first channel bandwidth and wherein the wide-bandwidth channel includes at least two legacy channels;

generating a first portion of the channel sounding field in accordance with the legacy wireless protocol, wherein the first portion of the channel sounding field corresponds to the first set of the plurality of tones; and

generating a second portion of the channel sounding field in accordance with a current wireless protocol, wherein the second portion of the channel sounding field corresponds to remaining tones of the plurality of tones.

9. The method of claim 8 further comprises:

generating a short training sequence as the legacy carrier detect field in accordance with a legacy version of an IEEE 802.11 protocol;

generating a long training sequence as the first portion of the channel sounding field in accordance with a legacy version of an IEEE 802.11 protocol; and

repeating the long training sequence as at least part of the second portion of the channel sounding field in accordance with a current version of an IEEE 802.11 protocol.

10. The method of claim 9, wherein generating the second portion of the channel sounding field further comprises:

generating tones within a guard band field between the at least two legacy channels of the wide-bandwidth channel.

11. The method of claim 8 further comprises:

combining the at least two legacy channels for a single input single output (SISO) wireless communication.

12. The method of claim 8 further comprises:

processing the at least two legacy channels in parallel for a multiple input multiple output (MIMO) wireless communication.

13. A radio frequency (RF) transmitter comprises:

a baseband processing module operably coupled to convert outbound data into an outbound symbol stream; and

a transmitter section operably coupled to convert the outbound symbol stream into outbound RF signals, wherein the baseband processing module is operably coupled to;

determine channel bandwidth of a channel that supports the wide bandwidth signals in the network;

determine overlap of legacy channel bandwidth with the channel bandwidth of the channel; and

provide a legacy readable preamble section within the channel where the legacy channel bandwidth overlaps the channel bandwidth of the channel.

14. The RF transmitter of claim 13, wherein the baseband processing module is further operably coupled to:

utilize at least a portion of payload spectrum of the channel that for packet header transmission, wherein the packet header transmission includes at least a portion of the legacy readable preamble.

15. The RF transmitter of claim 14, wherein the baseband processing module is further operably coupled to utilize the at least a portion of the payload spectrum by at least one of:

utilizing a same power spectral density for the packet header transmission and for the payload; and

utilizing a different power spectral density for the packet header transmission and for the payload.

16. The RF transmitter of claim 13, wherein the baseband processing module is further operably coupled to:

generate a wide-bandwidth preamble of the wide bandwidth signals for at least one of;

Carrier detection;

Gain control;

Frequency offset estimation;

Channel estimation;

Transmission Deference; and

Data demodulation.

17. A radio frequency (RF) transmitter comprises:

a baseband processing module operably coupled to convert outbound data into an outbound symbol stream; and

a transmitter section operably coupled to convert the outbound symbol stream into outbound RF signals, wherein the baseband processing module is operably coupled to;

generate a legacy carrier detect field;

generate a channel sounding field, wherein the channel sounding field includes a plurality of tones within the wide-bandwidth channel, wherein a first set of the plurality of tones corresponds to tones of a legacy channel sounding field; and

generate a legacy signal field, wherein, in time, the legacy signal field follows the channel sounding field, which follows the legacy carrier detect field.

18. The RF transmitter of claim 17, wherein the baseband processing module is further operably coupled to:

generate at least one additional channel sounding field that includes a second plurality of tones; and

generate another signal field, wherein the at least one additional channel sounding field follows, in time, the legacy signal field, and the another signal field follows the at least one additional channel sounding field.

19. The RF transmitter of claim 17, wherein the baseband processing module is further operably coupled to:

generate the legacy carrier detect field in accordance with a legacy wireless protocol, wherein a legacy channel of the legacy wireless protocol has a first channel bandwidth and wherein the wide-bandwidth channel includes at least two legacy channels;

generate a first portion of the channel sounding field in accordance with the legacy wireless protocol, wherein the first portion of the channel sounding field corresponds to the first set of the plurality of tones; and

generate a second portion of the channel sounding field in accordance with a current wireless protocol, wherein the second portion of the channel sounding field corresponds to remaining tones of the plurality of tones.

20. The RF transmitter of claim 19, wherein the baseband processing module is further operably coupled to:

generate a short training sequence as the legacy carrier detect field in accordance with a legacy version of an IEEE 802.11 protocol;

generate a long training sequence as the first portion of the channel sounding field in accordance with a legacy version of an IEEE 802.11 protocol; and

repeat the long training sequence as at least part of the second portion of the channel sounding field in accordance with a current version of an IEEE 802.11 protocol.

21. The RF transmitter of claim 17, wherein the baseband processing module is further operably coupled to generate the second portion of the channel sounding field by:

generating tones within a guard band field between the at least two legacy channels of the wide-bandwidth channel.

22. The RF transmitter of claim 19, wherein the baseband processing module is further operably coupled to:

combine the at least two legacy channels for a single input single output (SISO) wireless communication.

23. The RF transmitter of claim 19, wherein the baseband processing module is further operably coupled to:

process the at least two legacy channels in parallel for a multiple input multiple output (MIMO) wireless communication.