摘要:
Beams are used to communicate in a wireless network including mobile and stationary receivers. The network operates according to the IEEE 802.11p in wireless access to vehicular environments (WAVE). A direction from the mobile transceiver to the stationary receiver is predicted using geographic information available to the mobile transceiver. A set of signals are received in the mobile transceiver from the stationary transceiver, wherein the signals are received by an array of antennas, and wherein the signals are received using a set of beams, and wherein each beam is approximately directed at the stationary receiver. A signal-to-noise ratio (SNR) is measured for each beam, and the beam with an optimal SNR is selected as an optimal beam for communicating data between the mobile transceiver and the stationary transceiver.
摘要:
In an orthogonal frequency division multiplexing (OFDM) network, a set of pseudo random sequences (PRS) are stored at a transmitter and a receiver. Each OFDM symbol is mapped to subcarriers for a set of transmit antennas to produce a mapped symbol. The mapped symbol is encoded using a pseudo-random phase precoder (PRPP) and the PRS to produce a precoded symbol. An inverse fast Fourier transform (IFFT) is applied to the precoded symbol, and the encoded symbol is transmitted to the receiver using the set of transmit antennas.
摘要:
Beams are used to communicate in a wireless network including mobile and stationary receivers. The network operates according to the IEEE 802.11p in wireless access to vehicular environments (WAVE). A direction from the mobile transceiver to the stationary receiver is predicted using geographic information available to the mobile transceiver. A set of signals are received in the mobile transceiver from the stationary transceiver, wherein the signals are received by an array of antennas, and wherein the signals are received using a set of beams, and wherein each beam is approximately directed at the stationary receiver. A signal-to-noise ratio (SNR) is measured for each beam, and the beam with an optimal SNR is selected as an optimal beam for communicating data between the mobile transceiver and the stationary transceiver.
摘要:
In an orthogonal frequency division multiplexing (OFDM) network, a set of pseudo random sequences (PRS) are stored at a transmitter and a receiver. Each OFDM symbol is mapped to subcarriers for a set of transmit antennas to produce a mapped symbol. The mapped symbol is encoded using a pseudo-random phase precoder (PRPP) and the PRS to produce a precoded symbol. An inverse fast Fourier transform (IFFT) is applied to the precoded symbol, and the encoded symbol is transmitted to the receiver using the set of transmit antennas.
摘要:
A set of data symbols is selected from a set of modulation constellation, and a sample-mean of the set of data symbols is determined. Each data symbol is first shifted by the sample-mean to obtain a shifted data symbol, and then the shifted symbol is multiplied by a first constant to obtain a scaled data symbol. A second constant is added to the scaled data symbol to obtain a mapped data symbol. The sample-mean is multiplied by a third constant to obtain a sample-mean mapped symbol. The set of mapped data symbols and the sample-mean mapped symbol are then transmitted as a resource block.
摘要:
Channel state information in a closed-loop, multiple-input, multiple-output wireless networks is fed back from each mobile station to a base station by first determining a transmit covariance matrix R, and applying a singular value decomposition (SVD) R=UΣVH, where U, V are left and right singular vector matrices, Σ is a diagonal matrix with singular values. The matrix V includes column vectors V. A beamforming vector vmax=[1 exp(jΦ)exp(j2Φ) . . . exp(jΦ)]/√{square root over (N)}] is approximated by the column vector V having a maximum magnitude, where Φ is a real number. Then, only the angle Φ is fed back using a phase modulation mapping of the components exp(jΦ) onto the associated subcarrier.
摘要:
A set of data symbols is selected from a set of modulation constellation, and a sample-mean of the set of data symbols is determined. Each data symbol is first shifted by the sample-mean to obtain a shifted data symbol, and then the shifted symbol is multiplied by a first constant to obtain a scaled data symbol. A second constant is added to the scaled data symbol to obtain a mapped data symbol. The sample-mean is multiplied by a third constant to obtain a sample-mean mapped symbol. The set of mapped data symbols and the sample-mean mapped symbol are then transmitted as a resource block.
摘要:
Channel state information in a closed-loop, multiple-input, multiple-output wireless networks is fed back from each mobile station to a base station by first determining a transmit covariance matrix R, and applying a singular value decomposition (SVD) R=UΣVH, where U, V are left and right singular vector matrices, Σ is a diagonal matrix with singular values. The matrix V includes column vectors V. A beamforming vector vmax=[1 exp(jΦ)exp(j2Φ) . . . exp(jΦ)]/√{square root over (N)}] is approximated by the column vector V having a maximum magnitude, where Φ is a real number. Then, only the angle Φ is fed back using a phase modulation mapping of the components exp(jΦ) onto the associated subcarrier.
摘要:
The first and second nodes in a wireless network estimate first and second channel response. The first node quantizes the first channel response to produce a first bit sequence, and a feed-forward message, which is transmit as a feed-forward message to the second node. The second node quantizes the second channel response using the feed-forward message to produce and an estimate of the first bit sequence, a second bit sequence and a feed-back message, which is transmitted to the first node. Then, the first and second nodes delete bits in the respective bit sequences using the feed-back and feed-forward message to generate first and second private keys with low bit mismatch rate.
摘要:
Complex-valued waveform samples in time-domain, frequency-domain and spatial-domain are organized into a plurality of dimensions. A vector of complex-valued samples is extracted from a multidimensional sample buffer. An input transform is applied to a vector of complex-valued samples to produce two vectors of real-valued samples. Each real-valued sample vector is processed to produce a two-dimensional codebook matrix and to generate a vector of indices into the columns of the generated codebook. The two indices vectors are merged to produce an encoded index stream. The encoded index stream along with the two codebooks is used to produce real-valued sample vectors. An output transform is applied to two real-valued sample vectors to produce a vector of complex-valued samples.