Low power wireless communication system and protocol
First Claim
1. A wireless communication system comprising:
- at least one tag having a spread spectrum receiver; and
at least one access point having a spread spectrum transmitter;
wherein the access point is capable of transmitting a first signal encoded with a predetermined binary sequence, and the tag is capable of receiving the first signal and performing a fast Walsh transform using the predetermined binary sequence to establish an accurate frequency reference signal within the tag, the accurate frequency reference signal allowing the tag and access point to transfer information to one another via a wireless, spread spectrum communication link.
1 Assignment
0 Petitions
Accused Products
Abstract
A wireless communication system and protocol are disclosed. The system includes at least one tag and at least one access point. The access point transmits a beacon signal that includes a predetermined binary sequence such as a pseudonoise (PN) sequence. The tag typically does not include an expensive accurate frequency generator component, such as a crystal oscillator. The tag searches for the beacon signal using a fast Walsh transform. Specifically, the tag performs fast Walsh transforms on received data to locate the beacon signal. Once the beacon signal is located, an accurate frequency reference signal can be established at the tag, allowing the tag and access point to transfer information to one another via a wireless, spread spectrum communication link.
-
Citations
59 Claims
-
1. A wireless communication system comprising:
-
at least one tag having a spread spectrum receiver; and
at least one access point having a spread spectrum transmitter;
wherein the access point is capable of transmitting a first signal encoded with a predetermined binary sequence, and the tag is capable of receiving the first signal and performing a fast Walsh transform using the predetermined binary sequence to establish an accurate frequency reference signal within the tag, the accurate frequency reference signal allowing the tag and access point to transfer information to one another via a wireless, spread spectrum communication link. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A method performed in a wireless communication system, the method comprising:
-
transmitting the beacon signal over a wireless communications link;
receiving the beacon signal from the wireless communications link;
searching for the beacon signal by performing a fast Walsh transform using the digital data; and
establishing an accurate frequency reference signal based on digital data included within the beacon signal if the results of the fast Walsh transform indicate that the beacon signal has been located. - View Dependent Claims (13, 14, 15, 16, 17)
-
-
18. A wireless communication device comprising:
-
an antenna;
a spread spectrum receiver in electrical communication with the antenna; and
a processor in electrical communication with the receiver;
wherein an accurate frequency reference signal is established in the wireless communication device by receiving a first signal encoded with a predetermined binary sequence and performing a fast Walsh transform using the predetermined binary sequence of the first signal. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27)
-
-
28. A method performed in a wireless communication device, the method comprising:
-
receiving a beacon signal from a wireless communications link;
searching for the beacon signal by performing a fast Walsh transform using digital data included in the beacon signal; and
establishing an accurate frequency reference signal if the results of the fast Walsh transform indicate that the beacon signal has been located. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36)
-
-
37. A wireless communication device comprising:
-
an antenna;
a spread spectrum transceiver in electrical communication with the antenna; and
a processor in electrical communication with the transceiver;
wherein the wireless communication device is capable of transmitting a first signal encoded with a predetermined binary sequence, the first signal enabling a plurality of tags to establish an accurate frequency reference signal by performing a fast Walsh transform on the predetermined binary sequence. - View Dependent Claims (38, 39, 40, 41)
-
-
42. A method performed in a wireless communication device, the method comprising:
-
transmitting a first signal encoded with a first predetermined binary sequence;
receiving a second signal encoded with a second predetermined binary sequence;
generating digital data using the second signal; and
performing a fast Walsh transform on the digital data. - View Dependent Claims (43, 44, 45, 46, 47)
-
-
48. A method for reducing the amount of power consumed in a wireless communication device, the method comprising:
-
during a chip period, generating a first signal to be used in receiving for receiving data and ceasing the generation of the first signal when the data has been received; and
during the chip period, generating a second signal to be used in tranmitting data and ceasing generation of the second signal when the data has been transmitted. - View Dependent Claims (49, 50, 51, 52, 53)
-
-
54. A method for maintaining an accurate frequency reference signal in a wireless communication device, the method comprising:
-
searching for a beacon signal, the beacon signal being encoded with a binary sequency and being used to generate an accurate frequency reference signal within the wireless communication device; and
after locating the beacon signal, tracking the binary sequence such that the accurate frequency reference signal is maintained in the wireless communication device. - View Dependent Claims (55, 56)
-
-
57. A method for programing the taps of a RAKE filter used in a wireless communications device:
-
receiving a signal encoded with a binary sequence;
generating digital data from the signal;
performing a fast Walsh transforms on the digital data; and
using the results of the fast Walsh transforms to program the taps of the RAKE filter. - View Dependent Claims (58, 59)
-
Specification