摘要:
A multiple-input multiple-output (MIMO) system can transmit on multiple antennas simultaneously and receive on multiple antennas simultaneously. Unfortunately, because a legacy 802.11a/g device is not able to decode multiple data streams, such a legacy device may “stomp” on a MIMO packet by transmitting before the transmission of the MIMO packet is complete. Therefore, MIMO systems and methods are provided herein to allow legacy devices to decode the length of a MIMO packet and to restrain from transmitting during that period. These MIMO systems and methods are optimized for efficient transmission of MIMO packets.
摘要:
Current OFDM systems use a limited number of symbols and/or sub-channels to provide approximations for channel estimations and pilot tracking, i.e. phase estimations. For example, two training symbols in the preamble of a data packet are used to provide channel estimation. Four of the fifty-four sub-channels are reserved for providing phase estimation. However, noise and other imperfections can cause errors in both of these estimations, thereby degrading system performance. Advantageously, decision feedback mechanisms can be provided to significantly improve channel estimation and pilot tracking in OFDM systems. The decision feedback mechanisms can use data symbols in the data packet to improve channel estimation as well as data sub-channels to improve pilot tracking.
摘要:
Over the air or radiated testing of an RF microelectronic or integrated circuit device under test (DUT) that has an integrated millimeter wave (mmw) antenna structure, is described. The antenna structure may have multiple elements in an array design that may be driven and/or sensed by integrated RF transmitter and/or receiver circuitry. An interface printed wiring board (e.g., a tester load board or a wafer probe card assembly) has formed in it a mmw radiation passage that is positioned to pass mmw radiation to and/or from the integrated antenna of the DUT. Test equipment may be conductively coupled to contact points of the interface board, to transmit and/or receive signals for testing of the DUT and/or provide dc power to the DUT. A test antenna is designed and positioned to receive and/or transmit mmw radiation through the passage, from and/or to the integrated DUT antenna. Other embodiments are also described and claimed.
摘要:
A wireless content protection system includes a coordinator, a source device, and a sink device. The coordinator includes a scheduler. The source and sink devices each have a content protection manager. One of the content protection manager allocates and releases bandwidth via the coordinator for a test message and a response message for a round-trip time computation. The test message is transmitted in a source-to-sink channel time block. The response message is transmitted in a sink-to-source channel time block. The round-trip time is the period between the end of the source-to-sink channel time block and the beginning of the sink-to-source channel time block.
摘要:
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.
摘要:
A circular filtering system that prevents the problem of inter-symbol interference. The circular filtering system utilizes a buffer memory to store samples of a given symbol and provide only these samples to a linear filter such that the output of the filter, for any given symbol is formed by filtering only samples of that input symbol. Each symbol being filtered independent of other symbols hence eliminating inter-symbol interference caused by filtering. Where symbols are tolerant to a fixed phase shift for each symbol, the circular filtering system can be simplified by reducing the size of the buffer and introducing a multiplexer.
摘要:
A method of scaling at a receiver representations of training signals received from a transmitter. The method includes producing a frequency domain representation of at least one long training symbol received at the receiver and a frequency domain representation of a data symbol, and scaling the frequency domain representation of the at least one long symbol based on a largest coefficient in the frequency domain representation to produce a scaled frequency domain representation of the at least one long symbol.
摘要:
A multidimensional beamforming device that performs consecutive one-dimensional operations. For example, beamsteering for a two-dimensional array can be include a projection of a beam onto each of the respective axes of the array. In such a device, a first beamforming processing element is used to form multiple beams for each array output along a given row. In a preferred embodiment, sequential output vectors from the first processing element are then applied to a transposing or corner turning memory and the data are reformatted such that all elements on a given column of the array are applied to a second beam forming processing element.
摘要:
A hand-held ultrasound probe system includes integrated electronics within an ergonomic housing. The electronics includes control circuitry, beamforming and circuitry transducer drive circuitry. The probe electronics communicates with a host computer using an industry standard high speed serial bus.
摘要:
A media access controller (MAC) generates a composite packet having an optimized format for carrying audio, video, and data traffic. A header portion of the composite packet is encoded separately from a data portion of the composite packet. A physical device interface (PHY) is coupled to the MAC. The PHY encodes and decodes between a digital signal and a modulated analog signal. The PHY comprises a high rate physical layer circuit (HRP) and a low rate physical layer circuit (LRP). A radio frequency (RF) transmitter is coupled to the PHY to transmit data.