Abstract: Aspects of a method and system for reordered QRV-LST (layered space time) detection for efficient processing for multiple input multiple output (MIMO) communication systems are presented. The method may include receiving an ordered plurality of signals wherein each of the ordered plurality of received signals comprises information contained in an ordered plurality of spatial streams. Each spatial stream may comprise one or more frequency carriers, or tones. Information, or data, contained in a corresponding one of the ordered plurality of spatial streams may be detected. The order in which the information is detected may be determined for each individual frequency carrier.

Abstract: A filter settings generation operation includes sampling a communication channel to produce a sampled signal. The sampled signal is spectrally characterized across a frequency band of interest to produce a spectral characterization of the sampled signal. This spectral characterization may not include a signal of interest. The spectral characterization is then modified to produce a modified spectral characterization. Filter settings are then generated based upon the modified spectral characterization. Finally, the communication channel is filtered using the filter settings when the signal of interest is present on the communication channel. In modifying the spectral characterization, pluralities of spectral characteristics of the spectral characterization are independently modified to produce the modified spectral characterization. Modifications to the spectral characterization may be performed in the frequency domain and/or the time domain.

Abstract: Aspects of a method and system for minimizing effects of transmitter impairments in multiple input multiple output (MIMO) beamforming communication systems are presented. In one aspect of a system for minimizing effects of transmitter impairments, a MIMO transmitter may enable nulling of transmitter-induced noise by adjusting at least a portion of a plurality of signals transmitted based on a transmitter error vector magnitude (EVM). The transmitter may enable transmission of the plurality of signals subsequent to the nulling. In another aspect of a system for minimizing effects of transmitter impairments a MIMO receiver may enable nulling of transmitter-induced noise contained in a plurality of received signals based on a transmitter EVM. Each of the plurality of received signals may include information contained in a plurality of spatial streams. The receiver may enable detecting estimated values for the information contained in the plurality of spatial streams based on the nulling.

Abstract: Aspects of a method and system for utilizing Givens rotation expressions for quantization for a general beamforming matrix in feedback information. In one aspect of the invention, feedback information is computed at the receiving MIMO wireless device based on a geometric mean decomposition (GMD) method. The feedback information may include a matrix that describes a wireless medium. The matrix may represent a multiplicative product of at least one rotation matrix and at least one diagonal phase rotation matrix. Each of the rotation matrices may include at least one matrix element whose value is based on Givens rotation angle. The transmitting MIMO wireless device may subsequently transmit a plurality of signals via the wireless medium based on the received matrix information. The signal strength and/or signal to noise ratio (SNR) measurement (as measured in decibels, for example) associated with each of the transmitted plurality of signals may be about equal.

Abstract: New version packet data devices support a backwards-compatible signal format. New version devices operate within a first frequency band while old version devices operate within a second frequency band. The first frequency band differs from but overlaps with the second frequency band. The new version devices may operate on a first carrier frequency (within the first frequency band) while old version devices may operate at a second carrier frequency (within the second frequency band). The new version devices and/or the old version devices may also support carrier-less modulations. Preamble, header, and trailer portions of a new version signal include a plurality of spectral copies of a baseband modulated signal. One or more of these spectral copies of the baseband modulated signal is/are indistinguishable from corresponding components of an old version signal. The payload of the new version signal may be formed in the same manner or may be formed in have a wider bandwidth, higher data rate format.

Abstract: A network interface is presented that receives packet data from a shared medium and accomplishes the signal processing required to convert the data packet to host computer formatted data separately from receiving the data packet. The network interface receives the data packet, converts the analog signal to a digitized signal, and stores the resulting sample packet in a storage queue. An off-line processor, which may be the host computer itself, performs the signal processing required to interpret the sample packet. In transmission, the off-line process converts host-formatted data to a digitized version of a transmission data packet and stores that in a transmission queue. A transmitter converts the transmission data packet format and transmits the data to the shared medium.

Abstract: A filter settings generation operation includes sampling a communication channel to produce a sampled signal. The sampled signal is spectrally characterized across a frequency band of interest to produce a spectral characterization of the sampled signal. This spectral characterization may not include a signal of interest. The spectral characterization is then modified to produce a modified spectral characterization. Filter settings are then generated based upon the modified spectral characterization. Finally, the communication channel is filtered using the filter settings when the signal of interest is present on the communication channel. In modifying the spectral characterization, pluralities of spectral characteristics of the spectral characterization are independently modified to produce the modified spectral characterization. Modifications to the spectral characterization may be performed in the frequency domain and/or the time domain.

Abstract: A method for determining beamforming coefficients begins by obtaining channel information for a multiple tone communication. The method then continues by deriving the beamforming coefficients based on the channel information and a smoothness criteria.

Abstract: A network interface is presented that receives packet data from a shared medium and accomplishes the signal processing required to convert the data packet to host computer formatted data separately from receiving the data packet. The network interface receives the data packet, converts the analog signal to a digitized signal, and stores the resulting sample packet in a storage queue. An off-line processor, which may be the host computer itself, performs the signal processing required to interpret the sample packet. In transmission, the off-line process converts host-formatted data to a digitized version of a transmission data packet and stores that in a transmission queue. A transmitter converts the transmission data packet format and transmits the data to the shared medium.

Abstract: An efficient optimal maximum-likelihood output detector reducing the complexity of demodulation/decoding computations in multiple-input multiple-output communication systems. A plurality of received signals may be combined into a plurality of combined received signals by multiplication of a matrix representing the plurality of received signals with another matrix that meets certain conditions. The plurality of combined received signals may then allow for slicing operations as well as calculation of distance metrics with significantly reduced complexity.

Abstract: New version packet data devices support a backwards-compatible signal format. New version devices operate within a first frequency band while old version devices operate within a second frequency band. The first frequency band differs from but overlaps with the second frequency band. The new version devices may operate on a first carrier frequency (within the first frequency band) while old version devices may operate at a second carrier frequency (within the second frequency band). The new version devices and/or the old version devices may also support carrier-less modulations. Preamble, header, and trailer portions of a new version signal include a plurality of spectral copies of a baseband modulated signal. One or more of these spectral copies of the baseband modulated signal is/are indistinguishable from corresponding components of an old version signal. The payload of the new version signal may be formed in the same manner or may be formed in have a wider bandwidth, higher data rate format.

Abstract: A method and signal therfor embodied in a carrier wave for sending information from transmit stations to receive stations over a transmission medium of a frame-based communications network. The information is sent in transmit frames having a frame format comprising a fixed rate header, followed by a variable rate payload, followed by a fixed rate trailer. The fixed rate header includes a preamble. The preamble has a repetition of four symbol sequences for facilitating power estimation, gain control, baud frequency offset estimation, equalizer training, carrier sensing and collision detection. The preamble also includes a frame control field.

Abstract: A method of determining a start of a transmitted frame at a receiver on a frame-based communications network. A received transmitted frame is filtered using filter coefficients matched to a preamble symbol sequence to provide a correlation sequence. The correlation sequence is low-pass filtered and delayed to provide a delayed low-pass filtered correlation signal. The delayed low-pass filtered correlation signal is compared with the low-pass filtered correlation signal and a fixed predetermined threshold to provide a correlation difference indicator. Energy of the received transmitted frame is detected and the energy is low-pass filtered to provide a low-pass filtered energy signal. The low-pass filtered correlation signal is compared with the low-pass filtered energy signal to provide a correlation peak indicator. A logical-AND of the correlation difference indicator and the correlation peak indicator is formed to determine a match/no match comparison indicative of the start of a transmitted frame.

Abstract: A method for selecting frame encoding parameters to improve transmission performance for a transmitting frame being transmitted from a transmitting station to a receiving station over a transmission medium of a frame-based communications network is provided, the transmitting frame having a header segment and a payload segment, the header segment being transmitted using a fixed set of encoding parameters such that the header segment can be received and decoded by all stations on the network, the payload segment being transmitted using a variable set of payload encoding parameters, the transmitting station sending the transmitting frame using one set of the variable set of payload encoding parameters at a time. The receiving station receives and decodes the header and payload segments of each transmitting frame. The decoding includes computing frame statistics. A plurality of sets from the variable set of payload encoding parameters are selected to form a possible set of payload encoding parameters.

Abstract: This disclosure describes a simple spreading technique that improves performance for communication over fading channels with QPSK or BPSK modulation. The technique may comprise combining two symbols at the transmitter by applying a 2×2 transform, resulting in a 4-PAM or 16-QAM constellation. The receiver may utilize a 2-dimensional soft de-mapper to provide inputs to a soft-input decoder. This scheme can offer significant performance gains over fading channels with minimal additional complexity. This technique is most beneficial on systems with a weak code or no code at all. One application of this technique is for coded OFDM systems that experience frequency-selective fading. An example of such a system is the MBOA draft specification for UWB wireless communications.

Abstract: The present invention provides a frequency-diverse single-carrier modulation scheme that extends the usable SNR range of severely distorted channels. This scheme is advantageous for applications in which when the SNR is low and the transmitted spectrum contains unusable regions (e.g., spectral nulls due to radio-frequency interference ingress or egress). In one embodiment, the symbol baud rate is selected in order that unusable portions of the frequency response of the transmission channel are mapped onto usable portions of the frequency response of the transmission channel.

Abstract: A system and method for convolutionally encoding a stream of bits are disclosed. An embodiment of the present invention provides improved communication system performance in comparison to existing convolutional coding, such as that proposed for use in systems employing multi-band, orthogonal frequency division multiplexed signaling. A generator polynomial having a native code rate R=? may be used in combination with puncturing patterns supporting multiple codes rates. The resulting convolutional encoder exhibits improved performance at all code rates, and has no known disadvantages.

Abstract: Multi-mode WLAN/PAN MAC. A novel solution is presented in which a MAC (Medium Access Controller) is implemented that includes multiple functionality types. This MAC may include functionality supporting communication according to one or more of the IEEE 802.11 WLAN (Wireless Local Area Network) related standards and also to one or more of the standards generated by the IEEE 802.15.3 PAN (Personal Area Network) working group. By providing this dual functionality of a multi-mode WLAN/PAN MAC, a communication device may adaptively change the manner in which it communicates with other communication devices. For example, in an effort to maximize throughput and overall efficiency of communication within a communication system, certain of the various devices may change from using the WLAN related standards to using the PAN related standards, and vice versa, based on any one or more of a variety of operational parameters including system configuration.

Abstract: A method of determining a collision between two or more transmitting stations at one of the transmitting stations on a frame-based communications network. A transmitted frame header includes a cyclic preamble wherein identical copies of a preamble symbol sequence are transmitted sequentially. A collision is declared if an estimate of error power in second and third copies of the preamble minus an estimate of error power in third and fourth copies of the preamble exceeds a first threshold, or a maximum value of the norm of each term of a source field error vector minus a greater of the estimate of the error power in the second and third copies of the cyclic preamble and the estimate of the error power in the third and fourth copies of the preamble exceeds a second threshold.

Abstract: A method and apparatus for obtaining a channel estimate and a baud frequency offset estimate for a communications channel in a communications system. The communications system has a transmitter for transmitting to a receiver over the communications channel signals representing data appended to a preamble signal. The preamble signal is provided as a periodic plurality of preamble sequences, each preamble sequence being generated in accordance with: 1 32 ? ? k = 0 15 ? ? ? b k ? b mod ? ( k + n , 16 ) * = { 1 , n = 0 0 , n ? 0 . A signal representing the periodic plurality of preamble sequences is sent by a transmitter over the communications channel to a receiver and is received at the receiver as a received signal.