Wireless LAN with enhanced carrier sensing

• US 20030026198A1
• Filed: 07/31/2001
• Published: 02/06/2003
• Est. Priority Date: 07/31/2000
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Agere Systems Incorporated (Broadcom, Inc.)
• Inventors: Kriedte, Kai Roland, Diepstraten, Wilhelmus, Kamerman, Adriaan, Van Nee, D.J. Richard
• Granted Patent: US 7,463,589 B2
• Time in Patent Office: Days
• US Class Current: 370/208
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• 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

Medium access control device (301) for a mobile network station (3, 4, 5) or an access point (AP1) in a wireless local area network (1), having controlling means (302), processing means (303) and transmitting and receiving means (304); the controlling means (302) being arranged to control transmission and reception of radio frequency data signals containing data symbols; the transmitting and receiving means (304) being arranged for transmission and reception of electromagnetic data signals; the processing means (303) being arranged for detecting a first signal portion and a second signal portion in the received data signal, the second signal portion following the first signal portion and having a signal coding differing from a signal coding of the first signal portion.

Claims

1. Medium access control device for a mobile network station or an access point in a wireless local area network, comprising controlling means (302), processing means (303) and transmitting and receiving means (304);

said controlling means (302) being arranged to control transmission and reception of radio frequency data signals containing data symbols;

said transmitting and receiving means (304) being arranged for transmission and reception of electromagnetic data signals;

said processing means (303) being arranged for detecting a first signal portion in a received data signal, said processing means further comprising;

said processing means (303) are also arranged for detecting a second signal portion in said received data signal, wherein said second signal portion follows after said first signal portion, and said second signal portion comprises a second electromagnetic signal coding different from a first electromagnetic signal coding of said first signal portion.

2. The method according to claim 1, characterized in that said processing means, in order to detect said carrier signal in said second signal portion, is arranged for sampling a first part of said second signal portion with a first duration, a following second part of said second signal portion with a second duration and a final third part of said second signal portion with a third duration from said second received data signal, wherein said first duration equals said third duration, and the duration of the sum of said first, second, and third duration equals a complete data symbol duration;

and said processing means, in order to detect said carrier signal in said second signal portion, is further arranged for determining an auto-correlation between said first part of said second signal portion and said third part of said second signal portion.

3. The method according to claim 2, characterized in that the step of detecting the second signal portion further comprises filtering the second signal portion with a complex-valued processing filter of two IIR filters with biquad structure, capable of sampling said second signal portion at a sampling frequency which is twice the frequency of said second signal portion.

4. The method according to claim 2, characterized in that said first signal portion comprises OFDM as said electromagnetic first signal coding and said second signal portion comprises OFDM as said electromagnetic second signal coding

5. The method according to claim 2, characterized in that said first signal portion comprises BPSK, QPSK or other PSK as said first electromagnetic signal coding and said second signal portion comprises CCK, QAM or PSK as said second electromagnetic signal coding.

6. A method to be carried out by a medium access control device for a mobile network station or an access point in a wireless local area network, said medium access control device comprising controlling means, processing means and transmitting and receiving means;

said controlling means being arranged to control transmission and reception of radio frequency data signals containing data symbols;

said transmitting and receiving means being arranged for transmission and reception of electromagnetic data signals;

said method comprising the steps of;

detecting a first signal portion in a received data signal;

detecting a second signal portion in said received data signal, wherein said second signal portion follows after said first signal portion, and said second signal portion comprises a second electromagnetic signal coding different from a first electromagnetic signal coding of said first signal portion.