A Differential Turbo Detection Aided Sphere Packing Modulaled Space-Time Coding Scheme

Near-Capacity Irregular Precoded Linear Dispersion Codes

“…When a single symbol is transmitted, the resultant EXIT curve is a horizontal line, which is a property of the Gray labelling employed [8]. Therefore, regardless of the number of inner iterations employed, the MMSE detector of Figure 1 always outputs the same extrinsic information.…”

“…Serial Concatenated Codes (SCC) are capable of attaining an infinitesimally low BER, while maintaining a manageable decoding complexity [7] [8]. Since LDCs have the ability to approach the potential capacity of MIMO systems, it is natural to serially concatenate for example a simple convolutional channel code as the outer code and LDCs employed as the inner code in order to approach the MIMO capacity, while maintaining a near error-free BER performance.…”

Precoded Sphere-Packing-Aided Bit-Interleaved Differential Space-Time Coded Modulation Using Iterative Decoding

“…1 maps each block of b convolutionally encoded bits to a legitimate constellation point q l ∈ Q of the SP lattice D 4 , where we have b = log 2 L. Note that optimal mapping is chosen based on the analysis of EXIT. Further detail can be found in [8], as we will demonstrate in Section IV. The same mapper then represents the constellation point q l by two complex DSTBC symbols p l,1 (t) and p l,2 (t) of the two time slots using (2) and (3).…”

“…This scheme is compared to a non-precoded system when operating at E b /N 0 = 6 dB. The non-precoded system also employs iterative decoding between the soft SP demapper and the outer channel decoder, as described in [23] and [24], where the best anti-Gray mapping scheme that matches the outer code's EXIT curve was chosen as in [8]. Ideally, in order for the extrinsic information exchange between the inner and outer codes to converge at a certain E b /N 0 value, the extrinsic transfer curves should only intersect at the (I A M , I E M ) = (1.0, 1.0) point.…”

“…Another crucial issue in the context of Bit-Interleaved Coded Modulation using Iterative Decoding (BICM-ID) related schemes is the design of constellation mapping, which was studied in [7]. In [8], sphere packing (SP) modulation was proposed to improve the performance of differential space-time block codes (DSTBCs) [6], where the symbols transmitted in two time slots were jointly designed. As a result, the size of the new SP modulated constellation became L = 16 if originally quadrature phase-shift keying (QPSK) symbols were transmitted.…”