Amultiple accessscheme forthe uplinkof broadband wireless systems

A Turbo FDE Technique for Reduced-CP SC-Based Block Transmission Systems

“…Another FDE approach, with lower complexity, is the so-called iterative block decision-feedback equalization (IB-DFE), which does not use decoding within the iterative process. This approach, introduced in [4], was later extended and shown to be easily compatible with space diversity and multiple-input multiple-output (MIMO) systems [5], [6], as well as selected CP-assisted orthogonal frequency-division multiple-access (OFDMA)-type and code-division multiple-access (CDMA) schemes [7]- [9]. Since a full-length CP reduces the block transmission efficiency, the possibility of adopting a reduced CP (below the channel memory order), while keeping an essentially FFT-based implementation, deserves to be considered.…”

Impact of Radio Resource Allocation and Pulse Shaping on Papr of SC-FDMA Signals

“…It should be noted that the phase change is inverted between each of these matching pairs. The second row of Table 1 shows the phase rotation due to the spreading factor (SF) Q, which is generated from term in (7). Since the total phase rotation of the LFDMA signals are effectively the same, it follows that the PAPR will be identical.…”

“…The summation term in (7) indicates that the in-between samples are strongly correlated with their adjacent input symbols n x . The first exponential term in (7) represents the phase rotation in the LFDMA time domain samples according to the chosen RU, p. This occurs since the other RU# are frequency shifted versions of RU#0, as shown in Fig.…”

“…Here the term "spread" refers to subcarrier allocation for the multiple users. This technique is referred to as OFDM-FDMA with DFT spreading in [6,7]. Only distributed subcarrier mapping was considered in [6,7] since it results in a PAPR that is as low as conventional single-carrier systems.…”

“…This technique is referred to as OFDM-FDMA with DFT spreading in [6,7]. Only distributed subcarrier mapping was considered in [6,7] since it results in a PAPR that is as low as conventional single-carrier systems. In the 3G LTE standard, both distributed FDMA (DFDMA) and localized FDMA (LFDMA) are under consideration [4].…”