|
For Full-Text PDF, please login, if you are a member of IEICE,
or go to Pay Per View on menu list, if you are a nonmember of IEICE.
|
Demodulation Reference Signal Using Two-Dimensional Orthogonal Cover Code Mapping for Multi-Antenna/Point Transmission in LTE-Advanced Downlink
Kazuaki TAKEDA Yoshihisa KISHIYAMA Tetsushi ABE Takehiro NAKAMURA
Publication
IEICE TRANSACTIONS on Communications
Vol.E94-B
No.12
pp.3354-3361 Publication Date: 2011/12/01 Online ISSN: 1745-1345
DOI: 10.1587/transcom.E94.B.3354 Print ISSN: 0916-8516 Type of Manuscript: Special Section PAPER (Special Section on Cooperative Communications for Cellular Networks) Category: Keyword: LTE-Advanced, MIMO, CoMP, reference signal, orthogonal cover code,
Full Text: PDF(1.8MB)>>
Summary:
In the Long-Term Evolution (LTE)-Advanced downlink, a user-specific demodulation reference signal (DM-RS) is used to support channel estimation and data demodulation for user-transparent multi-antenna and/or multi-point (MA/P) transmission techniques. A hybrid code division multiplexing (CDM) and frequency division multiplexing (FDM) scheme is adopted as a DM-RS multiplexing scheme for up to eight data streams per user. A time-domain orthogonal cover code (OCC) is used for CDM since time domain orthogonality among OCCs offers good robustness against channel variation. However, in a medium-to-high mobility environment, orthogonality distortion occurs among OCCs, which results in performance degradation. In this paper, we propose a two-dimensional (2D)-OCC mapping that achieves two-dimensional orthogonality in the time and frequency domains to improve the performance of CDM-based DM-RSs while reducing the peak transmission power of the OFDM symbol which includes the DM-RSs. Simulation results show that the proposed 2D-OCC mapping is effective in improving the block error rate performance especially in medium-to-high mobility environments. Furthermore, it is shown that the 2D-OCC mapping effectively reduces the peak power compared to the time-domain OCC mapping.
|
|
|