Abstract: A time-interleaved (TI) analog-to-digital converter (ADC) is provided. The TI ADC generally comprises a clock generator, two or more ADCs, adjustable delay elements, and an estimator. The clock generator generates clock signals. Each ADC is associated with at least one of the clock signals so as to sample an input signal that is generally wide-sense stationary at sampling instants, where correlation function exist between samples from a two or more of the ADCs that is a function of the time differences between associated sampling instants. The estimator is coupled to each of the adjustable delay elements and each of the ADCs so as to calculate the correlation function and adjust the adjustable delay elements to account for sampling mismatch between the ADCs based at least in part on the correlation function.

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.

Abstract: System and method for providing multiple access in a multi-band, orthogonal frequency division multiplexed (multi-band-OFDM) communications system. A preferred embodiment comprises determining a transmission bandwidth to support a performance requirement and configuring transmission bands in the multi-band-OFDM communications system based upon the transmission bandwidth, wherein the transmission bands may be made up of smaller transmission bands bonded together. Further comprising initializing communications with the configured transmission bands. The use of bonded transmission bands can provide increased data rates and/or increased range performance.

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 method and apparatus for compensating a modulation imbalance effect in a communication device. In one embodiment, at least three sets of modulation imbalance parameters (MIPs) are estimated by executing an auto balance sequence. The at least three sets of MIPs correspond to a baseband signal configured to have at least three configurable frequencies, each of the at least three sets of MIPs corresponds to one of at least three configurable frequencies. The auto balance sequence is configured to provide an offset signal generated within a communication device to trigger generation of each one of the at least three configurable frequencies. The at least three sets of MIPs are filtered to select a filtered set. The modulation imbalance effect is compensated by using the filtered set to reduce distortion of the baseband signal in the communication device.

Abstract: Demodulation and decoding for frequency modulation (FM) receivers with radio data system (RDS) or radio broadcast data system (RBDS). An example of a method for processing a signal in a receiver includes quantizing a demodulated signal to generate bits in response to receipt of the demodulated signal. The method also includes grouping the bits into one or more blocks. The method further includes computing a syndrome for a block from the one or more blocks. Moreover, the method includes identifying error, corresponding to the syndrome, in the block based on type of demodulation. The type of demodulation includes a coherent demodulation and a differential demodulation. Furthermore, the method includes correcting the error in the block.

Abstract: A wireless device receives an input signal representing a signal of interest (e.g., one or more portions of a packet) on a wireless medium. The input signal may, in addition, contain narrowband interference signals. The wireless device removes the signal of interest from the input signal to produce a residue signal, and analyzes the residue signal to determine the presence of any interference bands in which narrowband interference signals may be present. The wireless device then removes the detected interference bands from the input signal. The residue signal may reveal the presence of interference signals, which might otherwise be hard to distinguish in the input signal. Thus, interference signals with power levels much lower than the power of the signal of interest may be detected and removed.

Abstract: A method for providing communication in a wireless network comprising one or more simultaneously operating pico networks includes dividing UWB spectrum into a plurality of frequency bands. These bands are formed into band groups. At least one band group is assigned to each one of the pico networks. At least pne time frequency code is assigned to symbols associated with each one of the pico networks on a transmission-by-transmission basis. A system for channelization of the spectrum includes a frequency-synthesized oscillator and a time frequency code generator configured to assign time-frequency codes to successive transmissions of a pico network such that the successive transmissions are transmitted in all frequency bands of a band group assigned to the pico network.

Abstract: A PHY entity for a UWB system utilizes the unlicensed 3.1-10.6 GHZ UWB band, as regulated in the United States by the Code of Federal Regulation, Title 47, Section 15. The UWB system provides a wireless pico area network (PAN) with data payload communication capabilities of 55, 80, 110, 160, 200, 320 and 480 Mb/s. The UWB system employs orthogonal frequency division multiplexing (OFDM) and uses a total of 122 sub-carriers that are modulated using quadrature phase shift keying (QPSK). Forward error correction coding (convolutional coding) is used with a coding rate of 11/32, 1/2, 5/8 and 3/4.

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

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

Abstract: Signaling in a medical implant based system. A method includes transmitting bits modulated with a predefined sequence in a band of channels by a first medical transceiver. The method includes detecting the predefined sequence by a second medical transceiver. The method also includes performing predetermined action if the predefined sequence is detected. In one example, the predetermined action includes determining presence of a signal.

Abstract: Power optimization in a medical implant based system. A method includes receiving a portion of a signal by a first transceiver. The method further includes determining, from the portion of the signal, a time duration after which a subsequent portion of the signal will be transmitted. The subsequent portion is transmitted at end of the portion. The method also includes entering into an inactive state for the time duration.

Abstract: System and method for providing multiple access in a multi-band, orthogonal frequency division multiplexed (multi-band-OFDM) communications system. A preferred embodiment comprises determining a transmission bandwidth to support a performance requirement and configuring transmission bands in the multi-band-OFDM communications system based upon the transmission bandwidth, wherein the transmission bands may be made up of smaller transmission bands bonded together. Further comprising initializing communications with the configured transmission bands. The use of bonded transmission bands can provide increased data rates and/or increased range performance.

Abstract: System and method for simplifying preamble detection and reducing power consumption in receivers. A preferred embodiment comprises a preamble made up of two sequences, a first sequence that is specified in the time domain and a second sequence that is specified in the frequency domain. The first sequence which comprises multiple copies of a time domain code sequence can allow easy detection of the preamble while the second sequence comprises multiple copies of a frequency domain code sequence and allows easy determination of the frequency response of the communications channel. A hierarchical sequence can be used to allow multi-stage correlation. This can result in a less complex correlator, hence lower power consumption. Piconets can use different code sequences to allow rapid determination of the source of a transmission without requiring the receiver to decode the entire transmission.

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 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.