Abstract: Aspects of the invention provide an enhanced chip-level linear space-time equalizer 118 for multiple-input-multiple-output (MIMO) multi-code CDMA systems reusing same spreading codes in different transmit antennas 114. Reuse of the spreading codes at the transmitter 104, 204 creates an on-time inter-stream interference component (or cross-talk among distinct transmit antenna signals) which reuse the same spreading code as the desired signal in the soft metric sequence of the MIMO CDMA receiver after MMSE space-time equalization. The equalizer 118 has a MMSE weighting vector that takes the despreading effect into account.

Abstract: Method for estimating and correcting a frequency offset between a local clock of a receiving transceiver and a remote clock of an emitting transceiver comprises receiving by said receiving transceiver, a signal emitted by the emitting transceiver, said signal lacking a continuous sinusoidal carrier and having at least one symbol, each symbol being emitted within a time frame having a first duration; sampling the signal by taking for each time frame a set of energy measurements of said signal; forming a matrix representative of said energy measurements; determining from said energy matrix, points of maximum of energy within each time frame; determining a line connecting a plurality of said points within each of said time frames; determining a slope of said line; calculating a frequency offset between the clocks of the emitting and receiving transceivers using the slope; and adjusting the receiving transceiver's clock frequency according to the frequency offset.

Abstract: The present invention concerns a receiver and a method for retrieving data from Ultra wideband radio transmission signals received by a receiver and transmitted in packets containing at least a preamble known to the receiver and a payload containing data unknown to the receiver. The payload data is formed of at least one burst containing at least one pulse. The method comprises the steps of receiving a signal corresponding to the preamble of a packet by a receiver; determining the energy of the received signal; determining weighting coefficients from the energy of the received signal; receiving a signal corresponding to the payload of a packet by a receiver; determining the energy of the received signal; calculating a threshold depending on the weighting coefficients; and applying a decision rule based on the sampled energy, weighted by said weighting coefficients and depending on said calculated threshold.

Abstract: Successive interference cancellation is performed with improved computational efficiency while offering performance approaching that of full CRC-based successive interference cancellation. In a “blind” interference cancellation technique, reconstructed streams are used for interference cancellation without regard to whether the reconstructed streams were properly decoded. In a “semi-blind” interference cancellation technique, decoder outputs from linear equalization can be used instead of decoder outputs from successive interference cancellation in those cases where linear equalization produces accurate decoding but successive interference cancellation does not.

Abstract: Method for estimating and correcting a frequency offset between a local clock of a receiving transceiver and a remote clock of an emitting transceiver comprises receiving by said receiving transceiver, a signal emitted by the emitting transceiver, said signal lacking a continuous sinusoidal carrier and having at least one symbol, each symbol being emitted within a time frame having a first duration; sampling the signal by taking for each time frame a set of energy measurements of said signal; forming a matrix representative of said energy measurements; determining from said energy matrix, points of maximum of energy within each time frame; determining a line connecting a plurality of said points within each of said time frames; determining a slope of said line; calculating a frequency offset between the clocks of the emitting and receiving transceivers using the slope; and adjusting the receiving transceiver's clock frequency according to the frequency offset.

Abstract: The present invention concerns a receiver and a method for retrieving data from Ultra wideband radio transmission signals received by a receiver and transmitted in packets containing at least a preamble known to the receiver and a payload containing data unknown to the receiver. The payload data is formed of at least one burst containing at least one pulse. The method comprises the steps of receiving a signal corresponding to the preamble of a packet by a receiver; determining the energy of the received signal; determining weighting coefficients from the energy of the received signal; receiving a signal corresponding to the payload of a packet by a receiver; determining the energy of the received signal; calculating a threshold depending on the weighting coefficients; and applying a decision rule based on the sampled energy, weighted by said weighting coefficients and depending on said calculated threshold.

Abstract: Successive interference cancellation is performed with improved computational efficiency while offering performance approaching that of full CRC-based successive interference cancellation. In a “blind” interference cancellation technique, reconstructed streams are used for interference cancellation without regard to whether the reconstructed streams were properly decoded. In a “semi-blind” interference cancellation technique, decoder outputs from linear equalization can be used instead of decoder outputs from successive interference cancellation in those cases where linear equalization produces accurate decoding but successive interference cancellation does not.

Abstract: Aspects of the invention provide an enhanced chip-level linear space-time equalizer 118 for multiple-input-multiple-output (MIMO) multi-code CDMA systems reusing same spreading codes in different transmit antennas 114. Reuse of the spreading codes at the transmitter 104, 204 creates an on-time inter-stream interference component (or cross-talk among distinct transmit antenna signals) which reuse the same spreading code as the desired signal in the soft metric sequence of the MIMO CDMA receiver after MMSE space-time equalization. The equalizer 118 has a MMSE weighting vector that takes the despreading effect into account.