Spectrally Efficient Multiuser Continuous-Phase Modulation Systems

FDMA System with Space–Time Encoded CPM Signals

“…Then, it executes N D times an outer iteration followed by an inner iteration. This way, ICI cancellation is performed as part of the decoding iterations and it results in an improved ICI cancellation [16]. On the final outer iteration, a decision is made on the transmitted data symbols b a 0 ; .…”

“…Signal y from MMSE/STC reaches the ICI cancellation block. The receiver carries out ICI cancellation through a set of single-user MAP detector/remodulator blocks, as described by Perotti et al [16]. The remodulators make use of the output of the MAP detector to compute the remodulated signal s k (i) (t) relative to the kth user and ith iteration.…”

“…At the receiving end, the system consists of a MIMO MMSE/STTC detector/decoder or MMSE/STBC detector/decoder and a low-complexity iterative algorithm to ICI cancellation [16].…”

“…The literature has already discussed the aspects of increasing the spectral efficiency of systems employing CPM and FDMA (e.g., in [16]), but STC coding in multiuser scenario has not been taken into consideration. This paper presents the operation of an FDMA system using CPM signals combined with STC (STBC and STTC).…”

Pilot based single user frequency offset estimation in spectrally-overlapping FDMA CPM systems

“…τ (4) τ (1) τ (2) τ ( where n (t) is zero mean (ZM) circular symmetric (CS) complex-valued (CV) AWGN with power spectral density T N 0 /E s , with N 0 the noise power spectral density and E s the energy per symbol period before normalization, and s (u) (t) is the unit-power contribution from user u to the normalized received signal:…”