DocumentCode :
3056186
Title :
An SNR-aware inter-symbol data-mapping precoding scheme for single-carrier systems
Author :
Ying-Tsung Lin ; Sau-Gee Chen
Author_Institution :
Dept. of Electron. Eng., Nat. Chiao-Tung Univ., Hsinchu, Taiwan
fYear :
2012
fDate :
2-5 Dec. 2012
Firstpage :
140
Lastpage :
143
Abstract :
This work proposes an inter-symbol data-mapping (ISDM) precoding scheme, which allows the receiver to adaptively select its most suitable data decoder based on the estimated SNR or channel conditions, for single carrier systems. For conventional modulation schemes, the only decoding method for traditional modulations, such as PSK and QAM, is to apply the maximum likelihood (ML) method after channel equalizations. Moreover, if the estimated SNR is unreliable enough to correctly decode the incoming signal, the received frame is usually discarded. As such, the communication system has to lower the symbol modulation order and re-transmit the data. The proposed ISDM scheme rearranges and re-maps a block of data bits to be transmitted so that they are correlated. Then, the receiver can decode the received signal by dynamically selecting the following three proposed decoders: post-equalization ML (PEML) decoder, full-rate most-significant-bit (FR-MSB) decoder and down-rate (DR) decoder based on estimated channel SNRs. For the FR-MSB decoder, its performance is close to the conventional BPSK decoder. On the other hand, PEML decoder can have roughly 2dB better performance than the FR-MSB one, while the DR decoder performs poorer than the FR-MSB one but with a lower computational complexity. Although the DR decoder has lower performance than the other two, its major advantage is able to decrease the ADC sampling rate with the help of multi-phase PLL. As such, the ISDM precoding scheme can provide the system better flexibility in data decoding.
Keywords :
channel estimation; communication complexity; equalisers; maximum likelihood decoding; phase locked loops; phase shift keying; precoding; quadrature amplitude modulation; radio receivers; sampling methods; wireless channels; ADC sampling rate; BPSK decoder; DR decoder; FR-MSB decoder; ISDM precoding scheme; ML method; PEML decoder; QAM; SNR-aware intersymbol data-mapping precoding scheme; channel SNR estimation; channel condition; channel equalization; communication system; computational complexity; data decoder; data decoding; data retransmission; down-rate decoder; full-rate most-significant-bit decoder; maximum likelihood method; modulation scheme; multiphase PLL; postequalization ML decoder; receiver; signal decoding; single-carrier system; symbol modulation order; Bit error rate; Decoding; Encoding; Phase shift keying; Receivers; Signal to noise ratio;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Circuits and Systems (APCCAS), 2012 IEEE Asia Pacific Conference on
Conference_Location :
Kaohsiung
Print_ISBN :
978-1-4577-1728-4
Type :
conf
DOI :
10.1109/APCCAS.2012.6418991
Filename :
6418991
Link To Document :
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