摘要:
A device (104, 106, 108) is provided for wireless communication. The device (104, 106, 108) includes a transmitter (200) operable to transmit an orthogonal frequency division multiplex symbol. The orthogonal frequency division multiplex symbol has a first set of copied tones adjacent a first end of the orthogonal frequency division multiplex symbol, a second set of copied tones adjacent a second end of the orthogonal frequency division multiplex symbol, and a plurality of data tones provided between the first and second sets of copied tones. The first and second sets of copied tones include copies of at least some of the plurality of data tones.
摘要:
The invention generally provides a method of intelligent frequency hopping such as in Bluetooth and Home RF networks. The method (100) includes the acts of sampling a plurality of channels in a frequency band and identifying each channel as a good channels or a bad channel (110), determining the size of a good window and the size of a bad window (120), and assigning a plurality of good channels to a good window (130) and a plurality of bad channels to a bad window (140). Accordingly, the method increases the reliability and throughput of wireless networks.
摘要:
The distance between a first Multi Band Orthogonal Frequency Division Multiplex (MB-OFDM) data transceiver and a second or more such transceiver is determined using known techniques. The radio frequency path loss between transceivers is estimated given said distance, using a known relationship between distance and path loss, and further accounting for line-of-sight or non-line-of-sight conditions if desired. This path loss value is added to the typically minimum transmit power level, absent path loss, needed for reliable data communication. This modified initial transmit power level is then used by the first transceiver to begin the known iterative feedback process of transmit power control (TPC). Because this modified initial transmit power level, based on distance, is closer to the final optimum level, convergence in the TPC process occurs in fewer steps and less time than had the initial transmit power been maximum power as is typical in known TPC systems.
摘要:
Transceiver circuitry for use in a multiple-input, multiple-output (MIMO), orthogonal frequency-division multiplexing (OFDM), communications environment, is disclosed. Error correction coding according to a fixed-block size code, such as low density parity check (LDPC) coding, is implemented. The codeword length, and codeword arrangement, are selected by determining a minimum number of OFDM symbol periods required for a payload size, and the number of available information bits in those symbol periods. A rule-based approach, for example in a table, is used to select the codeword length, and the number of codewords required. Shortening is then applied to the code, followed by determining whether puncturing or repeating of bits is necessary to efficiently use the available OFDM symbols.
摘要:
A wireless device for routing data in a mesh network is provided. The wireless device includes a component operable to obtain metrics related to one or more directly adjacent links in the mesh network and metrics received from one or more other nodes in the mesh network. The component is operable to apply parameters that include weighting to one or more of the metrics to compute one or more routes for routing data. The wireless devices also includes a transmitter that is operable to propagate to one or more adjacent nodes in the mesh network routing information related to the parameterized metrics obtained by the component.
摘要:
The invention generally provides a method of intelligent frequency hopping such as in Bluetooth and Home RF networks. The method (400) includes the acts of generating windows (410), sampling an original frequency (430), determining if the original frequency is of a desired frequency type (440), using the original frequency when the original frequency is the desired frequency type (460), and mapping the frequency to the desired frequency type when the original frequency is not the desired frequency type (450). Accordingly, the method increases the reliability and throughput of wireless networks.
摘要:
The present invention provides a versatile system for optimizing data fragmentation in a digital communications—particularly OFDM communications—system. A digital transmission system (100) is provided, having a PHY-level constraint. An array (104, 112) of data transmission parameters (106-110, 114-116), relating to the digital transmission system, is provided. A fragmentation construct (102) is provided, and adapted to determine a number of symbols required to transmit a given data transmission payload. The fragmentation construct calculates (118), based on the number symbols required, and on certain parameter information from the array, a number of bytes of data that must be transmitted in the given data transmission payload in order to minimize pad bits added to the data transmission payload.
摘要:
A system and method for channelization and data multiplexing in ultra-wideband (UWB) wireless communication system is described. The spectrum allocated for UWB in a multi-band OFDM (orthogonal frequency division multiplex) system is subdivided into various bands. A set of time frequency codes (TFC's) is defined, wherein each code specifies one of a plurality of unique band versus time sequences for a particular band group, for sequential data symbols of a given piconet. The separation of data words from multiple devices or multiple simultaneously operating piconets (SOP's) is provided by a combination of FDMA and TFC's. The combination of FDMA and TFC's provides a simplified interface between the MAC and PHY.
摘要:
A method for network coding includes generating a message matrix, where each column of the message matrix corresponds to one of K message packets and each element in a column of the message matrix corresponds to one of the symbols of the corresponding message packet. The method further includes generating a network code matrix to map the K message packets to N encoded packets, where any combination of K columns of the network code matrix is linearly independent and N is greater than K. The method also includes multiplying the message matrix by the network code matrix to generate a transmission matrix, where each column of the transmission matrix corresponds to an encoded packet for wireless transmission.
摘要:
A method for network coding using a near-maximum distance separable linear network code includes generating a message matrix where each column of the message matrix corresponds to one of K message packets and each element in a column of the message matrix corresponds to one of the symbols of the corresponding message packet. The method also includes generating a network code matrix to map the K message packets to N encoded packets, where any combination of K+1 columns of the network code contains at least K columns that are linearly independent. Further, the method includes multiplying the message matrix by the network code matrix to generate a transmission matrix, where each column of the transmission matrix corresponds to an encoded packet for wireless transmission.