Applications of representation theory to wireless communications
Designs, Codes and Cryptography
A Survey of Algebraic Unitary Codes
IWCC '09 Proceedings of the 2nd International Workshop on Coding and Cryptology
Effects of non-identical rayleigh fading on differential unitary space-time modulation
IEEE Transactions on Communications
IEEE Transactions on Signal Processing
Differential distributed cayley space-time codes
IEEE Transactions on Wireless Communications
Recursive space-time trellis codes using differential encoding
IEEE Transactions on Information Theory
Orthogonal space-time block codes with sphere packing
IEEE Transactions on Information Theory
Blind receiver for space-time differentially-encoded CDMA systems on multipath fading channels
ICICS'09 Proceedings of the 7th international conference on Information, communications and signal processing
The reference prior for complex covariance matrices with efficient implementation strategies
IEEE Transactions on Signal Processing
Labeling optimization of differential unitary space-time modulation
CAR'10 Proceedings of the 2nd international Asia conference on Informatics in control, automation and robotics - Volume 2
Coherent and differential space-time shift keying: a dispersion matrix approach
IEEE Transactions on Communications
Hi-index | 754.96 |
One method for communicating with multiple antennas is to encode the transmitted data differentially using unitary matrices at the transmitter, and to decode differentially without knowing the channel coefficients at the receiver. Since channel knowledge is not required at the receiver, differential schemes are ideal for use on wireless links where channel tracking is undesirable or infeasible, either because of rapid changes in the channel characteristics or because of limited system resources. Although this basic principle is well understood, it is not known how to generate good-performing constellations of unitary matrices, for any number of transmit and receive antennas and for any rate. This is especially true at high rates where the constellations must be rapidly encoded and decoded. We propose a class of Cayley codes that works with any number of antennas, and has efficient encoding and decoding at any rate. The codes are named for their use of the Cayley transform, which maps the highly nonlinear Stiefel manifold of unitary matrices to the linear space of skew-Hermitian matrices. This transformation leads to a simple linear constellation structure in the Cayley transform domain and to an information-theoretic design criterion based on emulating a Cauchy random matrix. Moreover, the resulting Cayley codes allow polynomial-time near-maximum-likelihood (ML) decoding based on either successive nulling/canceling or sphere decoding. Simulations show that the Cayley codes allow efficient and effective high-rate data transmission in multiantenna communication systems without knowing the channel