Abstract: A multiple description TCQ arrangement employs a trellis graph that is the tensor product of two trellis graphs. The codevectors of the tensor-product trellis, ci, are incorporated within trellis graph T1 and also within trellis graph T2. The incorporation within trellis graph T1 is effected by assigning the ci codevectors to sets, and by deriving therefrom codevectors for trellis graphs T1 and T2. The actual values that these codevectors take on are arranged to insure certain distortion results. Consequently, an improved arrangement is realized in which, two encoders are cooperatively generating separate trellis-coded descriptions of the input sequence. Three different fidelity levels can thus be achieved, which allows for use of receivers that are responsive to different rates, or the use of receivers that have adaptable rates.

Abstract: The present invention is directed to apparatus and method for encoding and decoding data within a wireless network such that a MS preferably does not require multiple receivers to handle communications from BTSs with varying numbers of antennas. In embodiments of the present invention, a space-time matrix is utilized to encode the data streams being transmitted from a BTS such that a BTS with fewer antennas would simply have an encoding matrix with one or more of the columns or rows removed from the matrix. In this way, the MSs within the wireless network can be designed to decode with the use of only a single space-time encoding matrix, this space-time encoding matrix working for BTSs with various numbers of antennas.

Abstract: An improved multi-antenna receiver is realized for detecting signals transmitted by a multi-antenna transmitter by summing signals received at the plurality of receiver antennas after multiplying each by a respective constant. The summed signal is applied to a maximum likelihood detector. The respective constants, &lgr;j, where j is an index designating a particular receiver antenna, are determined by evaluating the largest eigenvalue of the matrix &Lgr;A(&Lgr;*)T, where &Lgr; is a vector containing the values &lgr;j, and A is a matrix containing elements &agr;ij, which is the transfer function between the ith transmitter antenna to the jth receiver antenna. The &agr;ij terms are determined in the receiver in conventional ways.

Abstract: Good transmission characteristics are achieved in the presence of fading with a transmitter that employs a trellis coder followed by a block coder. Correspondingly, the receiver comprises a Viterbi decoder followed by a block decoder. Advantageously, the block coder and decoder employ time-space diversity coding which, illustratively, employs two transmitter antennas and one receiver antenna.

Abstract: In a receiver that includes a plurality of receiving antennas that supply signals to associated OFDM receiving modules, and the receiving modules provide signals that are applied to a detector, channel parameters that are needed for proper detection are estimated during normal operation, in addition to an initial estimate based on a known training sequence. In computing the channel impulse response estimates between the signal received at that receiving antenna and the various transmitting antennas, an nK0×nK0 matrix of terms (qxy[l]) is developed. The inverse of the matrix is then computed, and the computed matrix inverse is multiplied by a vector of terms (pi[l]), to obtain a vector of nK0-sample channel impulse response estimates.

Abstract: An improved multi-antenna receiver is realized for detecting signals transmitted by a multi-antenna transmitter by summing signals received at the plurality of receiver antennas after multiplying each by a respective constant. The summed signal is applied to a maximum likelihood detector. The respective constants, &lgr;j, where j is an index designating a particular receiver antenna, are determined by evaluating the largest eigenvector of the matrix A, where &Lgr; is a vector containing the values &lgr;j, and A is a matrix containing elements &agr;ij, which is the transfer function between the ith transmitter antenna to the jth receiver antenna. The &agr;ij terms are determined in the receiver in conventional ways.

Abstract: A system and method to reduce a ratio between a peak signal power and an average power (PAPR) in a multi-tone communication system. The system includes an encoder configured to receive a plurality of input bits and to generate a plurality of coded symbols based on the plurality of input bits, and a phase shift calculator configured to calculate a plurality of phase shift values for the coded symbols that minimizes the peak to average power ratio. The system further includes an encoding phase shifter coupled to the encoder and the phase shift calculator, configured to receive the phase shift values from the phase shift calculator and configured to phase shift the plurality of coded symbols to generate a plurality of phase shifted symbols.

Abstract: It is possible to realize a transmitter where a block of n symbols is encoded through an n×n matrix and transmitted over n antennas in n time intervals, only for n=2, 4, or 8. For all other numbers of antennas, the disclosed methodology permits the realization of full-rate rectangular designs, where the number of time intervals, p, is greater than n. In particular, the number of time intervals, p, is such that &rgr;(p)≧n, where &rgr;(p)=8c+2d, where c and d are such that p=b·24c+d, and b is an odd integer. Complex symbols can also be handled, but the rate for a design that allows use of any number of antennas is 0.5.

Abstract: Good transmission characteristics are achieved in the presence of fading with a transmitter that employs a trellis coder followed by a block coder. Correspondingly, the receiver comprises a Viterbi decoder followed by a block decoder. Advantageously the block coder and decoder employ time-space diversity coding which, illustratively, employs two transmitter antennas and one receiver antenna.

Abstract: A multiple description TCQ arrangement employs a trellis graph that is the tensor product, such as T1{circle around (X )} T2, of two trellis graphs, such as T1 and T2. The codevectors of the tensor-product trellis, ci, are incorporated within trellis graph T1 and also within trellis graph T2. The incorporation within trellis graph T1 is effected by assigning the ci codevectors to sets, and by deriving therefrom codevectors for trellis graphs T1 and T2. The actual values that these codevectors take on are arranged to insure certain distortion results. Specifically, the distortion measure of the tensor-product trellis is minimized, subject to the condition that the distortion measures of approximations made by decoders operating with the T1 and T2 trellises do not exceed a predetermined value. Consequently, an improved arrangement is realized in which two encoders are cooperatively generating separate trellis-coded descriptions of the input sequence.

Abstract: A differential detection approach allows communication without knowing the channel parameters, where the transmitter can include a plurality of transmitting antennas in excess of two. In the transmitter, each block of bits is mapped to a vector that is processed to develop a symbols vector, by employing mutually orthogonal vectors and the symbols vector of the previous block. The symbols vector is applied to a space-time mapping block, and thence to transmitting antennas. At the receiver, the received signals of a block are formed into vector, which is combined with a corresponding vector from the previous block in accordance with the mutually orthogonal vectors. The combined vector is sumined with combined vectors of the other receive antenmas, and the stumnmed result is applied to a minimum distance decoder module. The decoder module selects a most likely vector, and that vector is applied to a mapping that recovers the transmitted bits.

Abstract: A multiple description TCQ arrangement employs a trellis graph that is the tensor product, such as T1{circle over (X)}T2, of two trellis graphs, such as T1 and T2. The codevectors of the tensor-product trellis, c1, are incorporated within trellis graph T1 and also within trellis graph T2. The incorporation within trellis graph T1 is effected by assigning the c1 codevectors to sets, and by deriving therefrom codevectors for trellis graphs T1 and T2. The actual values that these codevectors take on are arranged to insure certain distortion results. Specifically, the distortion measure of the tensor-product trellis is minimized, subject to the condition that the distortion measures of approximations made by decoders operating with the T1 and T2 trellises do not exceed a predetermined value. Consequently, an improved arrangement is realized which, two encoders are cooperatively generating separate trellis-coded descriptions of the input sequence.

Abstract: An improved multi-antenna receiver is realized for detecting signals transmitted by a multi-antenna transmitter by summing signals received at the plurality of receiver antennas after multiplying each by a respective constant. The summed signal is applied to a maximum likelihood detector. The respective constants, &lgr;j, where j is an index designating a particular receiver antenna, are determined by evaluating the largest eigenvector of the matrix A, where &Lgr; is a vector containing the values &lgr;j, and A is a matrix containing elements &agr;ij, which is the transfer function between the ith transmitter antenna to the jth receiver antenna. The &agr;ij terms are determined in the receiver in conventional ways.

Abstract: A simple block coding arrangement is created with symbols transmitted over a plurality of transmit channels, in connection with coding that comprises only of simple arithmetic operations, such as negation and conjugation. The diversity created by the transmitter utilizes space diversity and either time or frequency diversity. Space diversity is effected by redundantly transmitting over a plurality of antennas, time diversity is effected by redundantly transmitting at different times, and frequency diversity is effected by redundantly transmitting at different frequencies. Illustratively, using two transmit antennas and a single receive antenna, one of the disclosed embodiments provides the same diversity gain as the maximal-ratio receiver combining (MRRC) scheme with one transmit antenna and two receive antennas.

Abstract: A trellis quantizer that produces an output sequence adapted for successively refinable decoded approximation employs a multi-level trellis graph. At any given level a next refinement level is obtained by replacing each transition of the trellis graph at the given level with a trellis graph. The codevectors of the refined trellis quantizer can be optimized for all levels of refinements by an iterative process that assesses the distortions resulting from modifying the codevectors. The optimizing is carried out concurrently for all levels of refinement, achieving thereby a quantizer that is optimized for whatever level of refinement the quantizer is asked to carry out. This optimization takes into account the probability distribution of incoming signal levels.

Abstract: A method and apparatus for increasing the data rate and providing antenna diversity using multiple transmit antennas is disclosed. A set of bits of a digital signal are used to generate a codeword. Codewords are provided according to a channel code. Delay elements may be provided in antenna output channels, or with suitable code construction delay may be omitted. n signals represent n symbols of a codeword are transmitted with n different transmit antennas. At the receiver MLSE or other decoding is used to decode the noisy received sequence. The parallel transmission and channel coding enables an increase the data rate over previous techniques, and recovery even under fading conditions. The channel coding may be concatenated with error correction codes under appropriate conditions.

Abstract: The prior art teachings for encoding signals and transmitting them over a plurality of antennas are advanced by disclosing a method for encoding for any number of transmitting antennas. Also disclosed is a generalized approach for maximum likelihood decoding where a decision rule is formed for all of the transmitting antennas of a transmitter, and a decision is made in favor of the transmitted symbols the minimize the equation ##EQU1## r.sub.t.sup.j is the signal received at time interval t, at receiving antenna j,h*.sub..epsilon..sbsb.t.sub.(i)j is the complex conjugate of the channel transfer function between the transmitter antenna that is transmitting symbol c.sub.i and receiving antenna j, and.delta..sub.t (i) is the sign of symbol c.sub.i in time interval t.