Performance bounds for cochannel interference cancellation within the current GSM standard

Properties, performance and practical interest of the widely linear MMSE beamformer for nonrectilinear signals

“…Indeed a quasi-rectilinear source is a source which can be written as a filtered version of a rectilinear source after a derotation operation by i −t/T , where T is the symbol duration for MSK and GMSK sources and half the symbol duration of the associated QAM modulation for OQAM source (see [11], [31]). In this context, the method proposed in Section V-C has to be adapted to take into account both the derotation and the filtering operation.…”

“…In the context of radio communications networks using rectilinear modulations such as BPSK or ASK modulations [29], it has been shown in particular in [7], [11], [12], [13], [21] that the WL MMSE receiver allows to implement SAIC of one intra-network interference in contrast to linear MMSE receiver. This SAIC concept can also be implemented for radio communication networks using quasi-rectilinear modulations, i.e., modulations whose complex amplitude can be considered, after a derotation operation, as a filtered version of a rectilinear modulation, such as MSK, GMSK or OQAM modulations [29], hence its great interest for GSM networks in particular [31], [26].…”

Single Antenna Interference Cancellation for 8PSK Signals in EGPRS

“…In [3], the method essentially treats the real and imaginary parts of the signal as antenna branches and uses the correlation of the signal on the two branches to suppress the interference. The authors in [3] calculate performance bounds for interference cancellation, but do not explicitly evaluate the performance of a receiver. The one-dimensional nature of the GMSK interferer lends itself to a signal that is highly correlated among the two virtual antenna branches, and thus lends itself to suppression via a matrix filter.…”

Enhanced Widely Linear Filtering to Make Quasi-Rectilinear Signals Almost Equivalent to Rectilinear Ones for SAIC/MAIC

“…Examples of QR modulations are π/2-BPSK, minimum shift keying (MSK) or OQAM modulations, while an example of approximated QR modulation is the Gaussian MSK (GMSK) modulation. One of the most important properties of WL filtering is its capability to perform SAIC of one R or QR multi-user CCI, allowing the separation of two users from only one receive antenna [7][8][9]. The effectiveness of this technology jointly with its low complexity explain why it is currently operational in most of GSM handsets, allowing significant network's capacity gains for the GSM system [9], [10].…”

“…In this context, the purpose of this paper is twofold. The first one is to get more insights into the existing SAIC/MAIC technology by proving analytically, which is completely original, that, contrary to what is implicitly accepted as true in the literature [6], [7], [9], [17][18][19][20], [29][30][31], [34][35][36], QR signals may be less efficient than R ones for SAIC/MAIC implemented from some standard WL filtering. Starting from this result, the second purpose of the paper is to propose and to analyse, partially analytically, which is also very original, for QR signals and frequency selective fading channels, an enhanced SAIC/MAIC technique based on a three-input WL FRESH receiver.…”