Abstract: A method for determining a gain compensation value for multiple ADCs sums an absolute value of a number of ADC output samples from each of the ADCs that may be collected while the ADCs are in normal operation. In one embodiment, the ratio of the sums of the absolute values of ADC output samples may reflect the difference in gains between the ADCs, and may be used to determine the ADC gain compensation value. A method for determining an offset compensation value between for multiple ADCs averages of a number of ADC output samples from each ADC collected while the ADCs are in normal operation. In one embodiment, a difference between the ADC sample averages may reflect the difference in magnitudes of the ADC offsets for each ADC, and may be used to determine the ADC offset compensation value.

Abstract: A system and method for wirelessly transmitting both real-time data streams and remote control signals is described. A first transceiver can be used for detecting remote control signals associated with an end device (e.g. a television), transforming these remote control signals into wireless signals, and transmitting the wireless signals. A second transceiver can be used for receiving the wireless signals and transforming the wireless signals into the recreated remote control signals. The recreated remote control signals can then be sent to a source device (e.g. a DVD player). Because wireless signals are used (instead of infrared (IR) signals, for example), the source device can be outside the line of sight of the end device and still respond to the remote control signals.

Abstract: A multi-carrier communication system such as an OFDM or DMT system has nodes which are allowed to dynamically change their receive and transmit symbol rates, and the number of carriers within their signals. Changing of the symbol rate is done by changing the clocking frequency of the nodes' iFFT and FFT processors, as well as their serializers and deserializers. The nodes have several ways of dynamically changing the number of earners used. The selection of symbol rate and number of earners can be optimized for a given channel based on explicit channel measurements, a priori knowledge of the channel, or past experience. Provision is made for accommodating legacy nodes that may have constraints in symbol rate or the number of carriers they can support.

Abstract: A method and apparatus for wirelessly transmitting real-time data streams is described. To ensure continuous data flow, fast diversity and slow diversity can be used. Fast diversity chooses a receive antenna based on received signal parameters, such as signal strength, during the transmission header and prior to information transfer. Slow diversity stores received signal parameters from previous packets, associates the parameters with a selected antenna, and uses the parameter history to denote a “default” antenna. Additionally, receive and/or transmit beam forming can be used to maintain continuous communication between stations. Beam forming, which combines antenna signals to maximize performance, is possible when at least two transmit/receive signal processing chains are available.

Abstract: A method of providing a protocol for rekeying between two stations is disclosed. The method can include providing a first set of messages for computing a new key and reserving an auxiliary storage area for the new key. The first set of messages comprises an enable exchange. The method also includes providing a second set of messages to obsolete an old key and switch to the new key. The second set of messages comprises a transition exchange. In one embodiment, the protocol includes rekeying between multiple stations, and the rekey coordinator sends the first set of messages to a plurality of rekey participants. The auxiliary storage area allows multiplexing in both the enable and transition exchanges, thereby facilitating an efficient and safe rekey operation.

Abstract: A method and apparatus to selectively disregard co-channel transmissions on a medium uses an automatic gain control/clear channel assessment (AGC/CCA) circuit to gather signal power information, which is used to establish receiver sensitivity thresholds. Raw and cyclical power measurements of a received signal are processed by the AGC/CCA circuit to determine whether a current received signal process should be halted, and a new signal acquisition sequence begun.

Abstract: An RF amplifier can include multiple gain stages, wherein each gain stage can be DC coupled to an adjacent gain stage. Each input gain stage can include either n-type gain transistors or p-type gain transistors. Multiple input gain stages can be designed/built by interleaving input gain stages of different types. Notably, an input gain stage including n-type gain transistors has a p-type bias transistor. Similarly, an input gain stage including p-type gain transistors has an n-type bias transistor. In this configuration, the bias transistor is the same type as the downstream gain transistors. Therefore, each bias transistor can accurately track the behavior of the transconductance devices of the next gain stage.

Abstract: A voltage-controlled oscillator (VCO) comprising a first circuit, a second circuit, a comparator circuit, and a control unit. The first circuit can determine an output common mode voltage associated with an output of the VCO. The second circuit can generate an upper control voltage limit and a lower control voltage limit associated with a control voltage received by the VCO based, at least in part, on the output common mode voltage. The comparator circuit can compare the control voltage to the upper and lower control voltage limits. The control unit can determine whether to change a switched capacitance associated with the VCO based, at least in part, on whether the control voltage is outside the upper and lower control voltage limits, thereby maintaining an optimal region of operation for the control voltage.

Abstract: The present invention provides an apparatus and method for optimizing power in order to increase capacity. Rather than having any terminal device limited to a specific maximum data rate, instead the terminal device data rate is limited by the power being used, such that the data rate can vary according to the distance that the terminal device is from the intended receiver.

Abstract: An N-stage inductor-less local oscillator (LO) buffer can include N?1 non-final stages and a final stage. The final stage can includes a gain circuit, a common-mode feedback circuit connected to the gain circuit, and a replica bias circuit that provides a predetermined voltage to the common-mode feedback circuit. The inductor-less LO buffer can advantageously reduce a power budget for its downstream mixer as well as provide a compact footprint.

Abstract: To efficiently transmit data on a wireless network, small packets that might otherwise be sent individually are aggregated into a “superframe”. This superframe can then be transmitted as a single, larger packet. To form this superframe, a plurality of tagged data packets can be aggregated into a packed aggregation block (PAB). Encapsulation data, e.g. protocol information, can be appended to the PAB. Wireless transmission information can bound the PAB and encapsulation data. Forming the superframe can be performed using an efficient combination of hardware and software. In one embodiment, aggregation of the tagged data packets can be performed by hardware without regard to the underlying protocol(s). Software can then provide protocol-handling support.

Abstract: A wireless local area network (WLAN) system can have multiple antennas to improve signal detection and decoding. A WLAN receiver in such a system includes multiple amplifiers that can appropriately size an incoming signal and an automatic gain control unit to process the received incoming signals. The amplifiers of a chain of the WLAN receiver, i.e. an antenna and associated receiver components, can be adjusted with computed gains. To optimize the wireless system detection and decoding, the automatic gain control unit can advantageously compute these gains for each amplifier in the WLAN receiver.

Abstract: A radio communication device is tested by forwarding relevant signal characteristic data derived at the physical (PHY) layer to the media access control (MAC) layer for processing, analysis and feedback to the radio circuit to improve performance. The relevant signal characteristics are forwarded to the MAC within (appended to) a data packet. Thus, the relevant signal characteristic is forwarded to the MAC along an existing data path (a path originally designed to transfer the receive frame only, but now transfers the combined receive frame with the attached radio characteristic). The radio characteristic may be used for testing and/or tuning the radio circuit. In one embodiment, the radio characteristic is a frequency domain representation of a received signal. The radio is tuned based on a channel estimate derived from comparison of frequency domain representations of transmitted and received signals.

Abstract: A peak detector can advantageously increase its bandwidth, i.e. its charging and discharging speed, while minimizing the ripple of its output signal by sensing the charging current of a storage device. In response to that charging current, the peak detector can control a discharge current, thereby accelerating its response. For example, the peak detector can reduce a discharge current in response to an increased charging current (which indicates a charging phase) and increase the discharge current in response to a decreased charging current (which indicates a discharge phase).

Abstract: A wireless communication device may be configured to transmit and receive data through a physical device, such as a cable. Relatively higher transmit radio frequency (RF) signals from the wireless communication device may be shifted to a relatively lower frequency, thereby enabling the relatively lower frequency signals to be carried by the physical device. Similarly, relatively lower frequency signals from the physical device may be shifted to relatively higher frequencies, thereby enabling the wireless communication device to receive the signals from the physical device. In one embodiment, the frequency of the RF signals may be between 2.3 and 2.7 GHz and the frequency of the relatively lower frequency shifted signals may be between 900 and 1100 MHz.

Abstract: Data is transmitted over a wireless channel. Convolutionally encoded data is received and the data is repetition encoding where a repetition rate associated with the repetition encoding is set to one of a plurality of possible rates. In some embodiments, data is repeated in the frequency domain. In some embodiments, data is repeated in the time domain.

Abstract: An interleaved ADC can advantageously provide synchronous sampling and time-multiplexed output. Differential I and Q input signals can first be stored by charging a plurality of capacitors. These stored differential signals can be buffered in a time-multiplexed sequence. For example, buffering can include transferring voltages stored by a first set of capacitors at a first time and then transferring voltages stored by a second set of capacitors at a second time. Advantageously, this time-multiplexing allow the ADC to be significantly smaller than conventional implementations of two-input ADCs. A folded mixer with gain control is also provided. This mixer can include a first stage having a first set of inductors and a plurality of first type transistors and a second stage having a second set of inductors and a plurality of second type transistors. The plurality of second type transistors in the second stage, which are in a folded configuration, can be driven by the first set of inductors in the first stage.

Abstract: A method for encrypted communications between a first transceiver and a second transceiver is provided. The method includes sending from a first transceiver to a second transceiver a request to initiate derivation of a new encryption key. The request to initiate a new encryption key derivation includes an exchange threshold indicative of when the new encryption key is to be used to encrypt communication packets.

Abstract: A transceiver includes a power control circuit in the transmitter that operates on a packet-by-packet basis. The transceiver can, for each packet, set a variable gain amplifier to a first gain and use predetermined gain increments to thereafter increase gain until a gain hold event. The gain hold event can be an expiration of a time duration allocated for changing gain or a desired power being reached, whichever event occurs first. The gain can be adjusted by a predetermined amount based on an operating condition.

Abstract: A multi-carrier communication system such as an OFDM or DMT system has nodes which are allowed to dynamically change their receive and transmit symbol rates, and the number of carriers within their signals. Changing of the symbol rate is done by changing the clocking frequency of the nodes' iFFT and FFT processors, as well as their serializers and deserializers. The nodes have several ways of dynamically changing the number of carriers used. The selection of symbol rate and number of carriers can be optimized for a given channel based on explicit channel measurements, a priori knowledge of the channel, or past experience. Provision is made for accommodating legacy nodes that may have constraints in symbol rate or the number of carriers they can support.