Frequency correction system for a wireless device communicating in a wireless local area network
First Claim
1. A frequency correction system for a wireless device operating in a wireless LAN in which communications are coordinated via a central hub, comprising:
- a frequency correction circuit that determines a frequency differential between a local frequency reference signal and a received signal and that provides a frequency offset signal indicative thereof;
an inverter, coupled to the frequency correction circuit, that inverts the frequency offset signal and that provides an inverted frequency offset signal;
a combiner, coupled to the inverter, that adjusts frequency of a transmit signal by the inverted frequency offset signal; and
a controller, coupled to the frequency correction circuit, the inverter and the combiner, that controls whether a transmit signal is adjusted in frequency by the inverted frequency offset signal wherein the controller detects signals received from the central hub and controls the inverter and combiner to adjust transmit frequency to correspond to a frequency of at least one signal received from the central hub.
10 Assignments
0 Petitions
Accused Products
Abstract
A wireless transceiver including an oscillator, a radio, a baseband processor and MAC device that performs apiori frequency offset correction. The radio converts between RF signals and baseband signals. The baseband processor includes a frequency correction loop, an inverter and a combiner. The frequency correction loop generates a frequency offset signal based on a frequency difference between an oscillator reference frequency and frequency of a received signal. The inverter inverts the frequency offset signal and the combiner adjusts frequency of a transmit signal by the inverted frequency offset signal. The MAC processes received packets, identifies packets received from an AP, provides packets to the baseband processor for transmission, and controls the baseband processor to adjust transmit signals to a frequency of the AP. The baseband processor may include a memory or filter to store or update frequency offset values.
-
Citations
18 Claims
-
1. A frequency correction system for a wireless device operating in a wireless LAN in which communications are coordinated via a central hub, comprising:
-
a frequency correction circuit that determines a frequency differential between a local frequency reference signal and a received signal and that provides a frequency offset signal indicative thereof; an inverter, coupled to the frequency correction circuit, that inverts the frequency offset signal and that provides an inverted frequency offset signal; a combiner, coupled to the inverter, that adjusts frequency of a transmit signal by the inverted frequency offset signal; and a controller, coupled to the frequency correction circuit, the inverter and the combiner, that controls whether a transmit signal is adjusted in frequency by the inverted frequency offset signal wherein the controller detects signals received from the central hub and controls the inverter and combiner to adjust transmit frequency to correspond to a frequency of at least one signal received from the central hub. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A wireless transceiver for communicating in a wireless LAN in which communications are coordinated via an access point (AP), comprising:
-
an oscillator that generates a frequency reference signal; a radio, coupled to the oscillator, that converts radio frequency (RF) signals transmitted in a wireless medium into baseband signals and that converts baseband signals into RF signals for transmission in the wireless medium; a baseband processor, coupled to the oscillator and the radio, comprising; a frequency correction loop that generates a frequency offset signal based on a frequency difference between a reference frequency and a received signal and that uses the frequency offset signal to synchronize the received signal; a received circuit, coupled to the frequency correction loop, that de-formats the adjusted received signal into packets; an inverter, coupled to the frequency correction loop, that inverts the frequency offset signal and that provides an inverted frequency offset signal; and a combiner, coupled to the inverter, that adjusts frequency of a transmit signal by the inverted frequency offset signal; and a media access control (MAC) device, coupled to the baseband processor, that processes received packets, that identifies packets received from the AP, that provides packets to the baseband processor for transmission, and that controls the baseband processor to adjust transmit signals to a frequency of the AP. - View Dependent Claims (8, 9, 10, 11, 12)
-
-
13. A method of apriori frequency offset for a wireless transceiver communicating in a wireless LAN in which communications are coordinated via a central hub, comprising:
-
generating a frequency offset signal in response to a received signal; determining whether the received signal was transmitted from the central hub; inverting the frequency offset signal if the received signal is from the central hub; and adjusting a transmit signal using the inverted frequency offset signal; and storing a frequency offset value representing a frequency offset signal wherein said inverting comprising generating the inverted frequency offset signal based on the stored frequency offset value. - View Dependent Claims (14, 15, 16, 17, 18)
-
Specification