Title | Noncoherent space-time equalization |
Publication Type | Journal Article |
Year of Publication | 2003 |
Authors | Schober, R., and S. Pasupathy |
Journal | Wireless Communications, IEEE Transactions on |
Volume | 2 |
Pagination | 537 - 548 |
Date Published | may. |
ISSN | 1536-1276 |
Keywords | adaptive filters, adjacent channel interference, antenna arrays, approximations, carrier synchronization loop, CCI, channel phase variations, cochannel interference, coherent receivers, coherent STE, decision feedback equalisers, differential phase shift keying, diversity, diversity reception, fast filter adaptation, interference suppression, intersymbol interference, ISI, land mobile radio, least squares approximations, M-ary differential phase-shift keying, multiple receive antennas, NDFE, NMPSK, noncoherent decision feedback equalization, noncoherent linear equalization, noncoherent recursive least squares algorithms, noncoherent sequence estimation, noncoherent space-time equalization, receiving antennas, RLS algorithm, sequential estimation, signal-to-distortion ratio, synchronization |
Abstract | In this paper, noncoherent equalization is combined with multiple receive antennas. The resulting noncoherent space-time equalization (NSTE) schemes are analyzed and compared with the corresponding coherent receivers. In particular, noncoherent linear equalization (NLE), noncoherent decision-feedback equalization (NDFE), and noncoherent sequence estimation (NSE) are considered. For NLE and NDFE novel approximations for the signal-to-distortion ratio (SDR) are derived and verified by simulations. It is shown that NSTE can suppress interfering users and exploit diversity as efficiently as coherent STE. However, NSTE is more robust against channel phase variations than the combination of coherent STE and synchronization. Robust noncoherent recursive least squares (NC-RLS) algorithms, which compare favorably with the conventional RLS algorithm with additional carrier synchronization loop, are proposed for fast filter adaptation. |
URL | http://dx.doi.org/10.1109/TWC.2003.811185 |
DOI | 10.1109/TWC.2003.811185 |