Abstract:
A radar detection technique in a WLAN device can include a short pulse detection technique and a long pulse detection technique that can be performed using multiple receive chains. Short pulse detection is particularly effective when the incoming signal includes one or a limited number of main pulses and some residual pulses. In contrast, long pulse detection is particularly effective when the incoming signal is longer, thereby allowing various characteristics of the incoming signal to be accurately measured.
Abstract:
A system and method are described for binding together a plurality of wireless data communications channels, whereby an aggregate throughput improvement is realized. A master channel amongst the channels to be bound is compatible with existing standards-based wireless data communications equipment. The master channel serves to perform MAC association and flow control. Aggregate throughput is improved by sending and receiving either multiple sets of separately encoded packets, commonly encoded packets or redundantly encoded packets.
Abstract:
To avoid interference with radar systems in the 5GHz, wireless devices detect radar and vacate any channels currently used by the radar system. In a channel switching technique, if the new channel is radar-exempt, then normal operation commences on the new channel. If the new channel is non-radar-exempt, then normal operation commences on a temporary radar-exempt channel and an aggregate background scan can be performed on the new channel. If no radars are detected using the aggregate background scan, then operation is switched from the temporary channel to the new channel.
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:
A multi-user OFDM or DMT communication system has nodes which are allowed to transmit continuously on one or just a few of the system's frequency sub-channels, while the other nodes avoid putting any signal into those sub-channels. Simple low data rate nodes are allowed to use a small number of sub-channels while more complicated nodes use the remainder, and preferably functionality is provided to ensure that adjacent sub-channels are reliably spaced apart in frequency so that they do not bleed over into one another; to ensure that signals from all nodes arrive at the base station with well-aligned symbol transitions (symbol synchronization); and to ensure that signals from the various nodes arrive at the base station with similar power levels (power control). Frequency assignment strategies at a base station range from one fixed sub-channel per node to a hopped group of sub-channels per node.
Abstract:
A dual band radio is constructed using a primary and secondary transceiver. The primary transceiver is a complete radio that is operational in a stand alone configuration. The secondary transceiver is a not a complete radio and is configured to re-use components such as fine gain control and fine frequency stepping of the primary transceiver to produce operational frequencies of the secondary transceiver. The primary transceiver acts like an intermediate frequency device for the secondary transceiver. Switches are utilized to divert signals to/from the primary transceiver from/to the secondary transceiver. The switches are also configured to act as gain control devices. Antennas are selected using either wideband or narrowband antenna switches that are configured as a diode bridge having high impedance at operational frequencies on control lines that bias the diodes.
Abstract:
A dual band radio is constructed using a primary and secondary transceiver. The primary transceiver is a complete radio that is operational in a stand alone configuration. The secondary transceiver is a not a complete radio and is configured to re-use components such as fine gain control and fine frequency stepping of the primary transceiver to produce operational frequencies of the secondary transceiver. The primary transceiver acts like an intermediate frequency device for the secondary transceiver. Switches are utilized to divert signals to/from the primary transceiver from/to the secondary transceiver. The switches are also configured to act as gain control devices. Antennas are selected using either wideband or narrowband antenna switches that are configured as a diode bridge having high impedance at operational frequencies on control lines that bias the diodes.
Abstract:
A Viterbi decoding system interprets bits in received QAM constellations as many-valued parameters rather than binary valued parameters. It performs the Viterbi algorithm using these many-valued parameters to provide results superior to hard decision decoding. Rather than applying a hard 0-1 function to the QAM data, the system uses a non-stepped linear or curved transfer function to assign values to the bits. In another aspect, a system differentiates between data bits based on their estimated reliability, giving more emphasis to decoding reliable bits than unreliable bits using any of a variety of techniques. By differentiating between good and bad bits and de-emphasizing or ignoring unreliable bits, the system can provide a significant reduction in uncorrectable errors and packet loss.
Abstract:
Specific bits of an incoming transmission are compared against a predetermined bit pattern. If the selected bits do not match the predetermined bit pattern, then the incoming transmission is rejected as a false packet. The predetermined bit pattern can include legal values for predetermined bits in a plurality of fields. Notably, these legal values are set by a networking standard. A parity check may check may be performed in addition to checking for predetermined bits in other fields. A user interface can be used to determine the predetermined bit pattern.