Abstract: The present invention provides a method for generating a timing offset signal applied to a sampling device for recovering a symbol stream from a broadcast signal by characterizing the dispersion of received signal. Preferably, the method includes steps for generating a derivative signal approximating the derivative of the symbol stream, producing a constant representative of an expected symbol stream, and multiplying the derivative signal, the constant, and a signal one of corresponding to and approximating the symbol stream to thereby generate the timing offset signal. A dispersion characterizing receiver and a digital signal processor employed therein are also described.

Abstract: In at least some embodiments, a method for mitigating interference between an Ultra Wideband (UWB) device and a non-UWB device is provided. The method includes, dynamically determining if a frequency channel associated with the non-UWB device is being used. If the frequency channel is being used, the method adjusts a UWB frequency band used for UWB signal transmission.

Abstract: In at least some embodiments, a method is provided. The method includes receiving samples from a first input channel and a second input channel. The method further includes controlling commutators to selectively switch samples between the first and second input channels for input to a radix-2 butterfly. The method further includes continuously activating the radix-2 butterfly while processing samples received from the first input channel followed by samples received from the second input channel.

Abstract: A system is provided that includes a first device 110A that transmits an information symbol with a zero-padded suffix (ZPS) and a second device 110B that receives the information symbol with the zero-padded suffix. The second device 110B performs a Fourier transform on at least one sample of the information symbol before a ZPS sample is overlapped-and-added to another sample of the information symbol.

Abstract: 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.

Abstract: The present disclosure is directed to a transmitter 200 that includes a first block encoder 450 operable to block encode at least a first portion of a multi-band orthogonal frequency division modulation signal. The transmitter 200 also includes a convolution encoder 304 operable to convolution encode the output of the first block encoder 450. A method of communicating is also disclosed. The method comprises block encoding a first portion of a message to produce a first outer code word. The method includes convolution encoding the first outer code word to produce a first inner code word. The method also includes transmitting the first inner code word as part of a multi-band orthogonal frequency division modulation signal.

Abstract: A method of wirelessly communicating is disclosed. The method comprises determining a matrix W based in part on limiting a plurality of active interference cancellation tone values (416), determining the active interference cancellation tone values (416) based on W and based on a plurality of information data values (410), and transmitting an orthogonal frequency division multiplex signal (310) based on the plurality of active interference cancellation tone values (416) and the information data values (410).

Abstract: A method of wirelessly communicating is disclosed. The method comprises generating a plurality of tones for a wideband orthogonal frequency division multiplex symbol (310), the tones including a plurality of contiguous zero-valued tones, inverse Fourier transforming the tones to a plurality of time-domain samples (312), copying a plurality of the time-domain samples as a portion of a cyclic block (314), the cyclic block (314) contiguous with the time-domain samples (312), time-domain window filtering the time-domain samples (312) and the cyclic block (314) to form a portion of the wideband orthogonal frequency division multiplex symbol (310), wherein the time-domain window filter (350) is a function ?(k) having the property that ?(k)+?(k+Nfft) is about equal to a constant ? where Nfft is the number of tones, and transmitting the wideband orthogonal frequency division multiplex symbol (310).

Abstract: 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.

Abstract: In MIMO wireless communications employing LMMSE receiver, the symbols transmitted through a transmit antenna are estimated at the receiver in the presence of interference consisting of two main components: one due to the additive noise and the other due to (interfering) symbols transmitted via the remaining antennas. This has been shown to hamper the performance of a communication system resulting in incorrect symbol decisions, particularly at low SNR. IMMSE has been devised as a solution to cope with this problem; In IMMSE processing, the symbols sent via each transmit antenna are decoded iteratively. In each stage of processing, the received signal is updated by removing the contribution of symbols detected in the previous iterations. In principle, this reduces the additive interference in which the desired symbols are embedded in. Therefore, the interference level should reduce monotonically as one goes down in processing order.

Abstract: A method comprising wirelessly transmitting and receiving a data signal in an orthogonal frequency division multiplexing (OFDM) system. The method further comprises, in the frequency domain, at least partially removing overlap between a first received subcarrier frequency data and a second received subcarrier frequency data.

Abstract: The present invention provides an enhanced channel estimator for use with an orthogonal frequency division multiplex (OFDM) receiver employing scattered pilot channel estimates. In one embodiment, the enhanced channel estimator includes a time interpolation estimator configured to provide time-interpolation channel estimates having at least one image for a portion of carriers having the scattered pilot channel estimates. The enhanced channel estimator also includes a frequency interpolation estimator coupled to the time interpolation estimator and configured to provide frequency-interpolation channel estimates for each carrier based on image suppression through balanced-error filtering.

Abstract: A system and method implement very high data rate baseband DACs suitable for wireless applications related to new standards (e.g. Ultra-Wide Band) using CMOS processes allowing an integrated solution with the deep-submicron CMOS digital baseband. A single CMOS block working at full speed is discarded in favor of several blocks, each working at a fraction of the original data rate.

Abstract: A wireless device (10, 12) is provided that distinguishes between multiple piconets. The wireless device (10, 12) includes a preamble component (160, 162, 164, 166) and a correlator (150) component. The preamble component (160, 162, 164, 166) provides a preamble (120) for a wireless fixed frequency interleaving transmission, and the correlator component (150) distinguishes a wireless transmission based on the preamble (120). A circuit (180) is provided for a wireless receiver to despread a hierarchical sequence (120) made by spreading an M-length sequence (110) with an N-length sequence (112). The circuit (180) includes a first and second despreaders (185, 190). The first despreader (185) is coupled to a signal input to despread a received signal. The signal is a fixed frequency interleaved transmission. The second despreader (190) is coupled to an output of the first despreader (185). The second despreader (190) despreads the output of the first despreader (185) with a second sequence.

Abstract: A transmitter 200 is provided. The transmitter 200 comprises a mapper 207 operable to map a bit stream into a plurality of tones to promote high data rate multi-band orthogonal frequency division multiplex communication, wherein the tones can take on sixteen or more different values 300. In another embodiment a communications system 1360 is provided that includes a transceiver 1362 that has two or more antennas 1394 and 1396. The transceiver 1362 transmits a first multi-band orthogonal frequency division multiplex signal in multiple input/multiple output mode and receives a second multi-band orthogonal frequency division multiplex signal in multiple input/multiple output mode. In another embodiment, a transceiver 200, 202 transmits a first multi-band orthogonal frequency division multiplex symbol concurrently on a plurality of sub-bands and receives a second multi-band orthogonal frequency division multiplex symbol concurrently on a plurality of sub-bands.

Abstract: The present invention provides a versatile system for selectively spreading carrier data across multiple carrier paths within an Orthogonal Frequency Division Multiplexing (OFDM) system (200), particularly an ultra-wideband (UWB) system. The present invention provides a data input (202), which passes data to a randomizer (204). The data then passes to a convolutional code function (206), the output of which is punctured by puncturing function (208). An interleaver function (210) receives the punctured code data, and cooperatively operates with a mapper element (218) to prepare the coded data for pre-transmission conversion by an IFFT (220). The mapper element (218) comprises a dual carrier modulation function (216), which associates and transforms two punctured code data elements into a format for transmission on two separate signal tones.

Abstract: The present invention provides a versatile system for selectively altering or shaping transmission signals in an ultra-wideband communications system (100). The system provides a serial to parallel conversion function (102) with a serial data input (116). The serial to parallel conversion function converts the serial data and outputs it in parallel format. An adjustment function (104) receives the now parallel data and selectively alters the parallel data responsive to some code or vector (118). A frequency-to-time-domain conversion function (106) receives the selectively altered parallel data and transmits it to a parallel-to-serial conversion function 108. The now serial data transfer through an OFDM prefix/suffix function 110 and a digital-to-analog conversion function 112, to an up conversion mixer function 114. Encoded digital data bits are input, converted to parallel format, and passed to the spectrum adjustment function, which provides selective adjustment of specific data units (i.e.

Abstract: A wireless device 10, 12 that distinguishes between multiple piconets is provided. The wireless device 10, 12 includes a preamble component operable to provide a preamble for a wireless fixed frequency interleaving transmission. The wireless device 10, 12 also includes a correlator component operable to distinguish a wireless transmission based on the preamble. The preamble is based on a 128-length sequence 120, 136, 144, formed using a 16-length sequence and a 8-length sequence. The 16-length sequence is selected from the group consisting of a first 16-length sequence 110, a second 16-length sequence 132, and a third 16-length sequence 140. The 8-length sequence is selected from the group consisting of a first 8-length sequence 112, a second 8-length sequence 134, and a third 8-length sequence 144.

Abstract: A transmitter 200 is provided. The transmitter 200 comprises a block encoder 203 operable to encode a bit stream using a first block size for a first portion of a message according to an orthogonal frequency division multiplex protocol and a second block size for a second portion of the message.

Abstract: System and method for signaling control information in a multi-carrier communications system to transmit data. A preferred embodiment comprises demodulating a first carrier that is used for transmitting a control channel transmission, determining a second carrier that is used for transmitting a data channel transmission based upon the demodulated control channel transmission, and demodulating the second carrier to obtain the data channel transmission. Additionally, designs for multi-carrier receivers are provided.