Title :
Linear Minimum Mean Square Turbo Equalization with 16QAM Multiple Trellis Coded Modulation
Author :
Nysaeter, Asgeir ; Otnes, Roald
Author_Institution :
Unik-Univ. Grad. Center, Kjeller
Abstract :
Linear minimum mean square error (LMMSE) turbo equalization with Gray mapped rate 3/4 1times16QAM and rate 6/8 2times16QAM trellis coded modulation (TCM) are compared on an unknown and time-varying frequency-selective channel. Frequency hopping is used for increased diversity, and the channel is tracked by linear interpolation between training sequence based estimates where a training sequence is inserted into the start and end of each frequency hop block. The TCM codes are optimized with regard to good low SNR performance. Turbo equalization with 2times16QAM TCM shows the best bit error performance, due to increased diversity relative to 1times16QAM TCM and better low SNR performance. The search procedure for finding optimum 2times16QAM codes is described.
Keywords :
channel estimation; diversity reception; equalisers; error statistics; frequency hop communication; interpolation; least mean squares methods; linear codes; optimisation; quadrature amplitude modulation; search problems; sequences; trellis coded modulation; turbo codes; wireless channels; 16QAM multiple trellis coded modulation; TCM code optimisation; bit error performance; frequency hop block; linear interpolation; linear minimum mean square turbo equalization; search procedure; time-varying frequency-selective channel; training sequence; Chirp modulation; Communication channels; Concatenated codes; Equalizers; Frequency diversity; Frequency estimation; Intersymbol interference; Iterative decoding; Labeling; Modulation coding;
Conference_Titel :
Vehicular Technology Conference, 2006. VTC-2006 Fall. 2006 IEEE 64th
Conference_Location :
Montreal, Que.
Print_ISBN :
1-4244-0062-7
Electronic_ISBN :
1-4244-0063-5
DOI :
10.1109/VTCF.2006.400
