TY - JOUR
T1 - Adaptive hierarchical modulation for simultaneous voice and multiclass data transmission over fading channels
AU - Hossain, Md Jahangir
AU - Vitthaladevuni, Pavan Kumar
AU - Alouini, Mohamed Slim
AU - Bhargava, Vijay K.
AU - Goldsmith, Andrea J.
N1 - Funding Information:
Manuscript received August 19, 2003; revised October 15, 2004; accepted September 25, 2005. This work was supported in part by the Center of Transportation Studies (CTS) through the Intelligent Transportation Systems (ITS) Institute, Minneapolis, MN, and in part by the Natural Sciences and Engineering Council of Canada (NSERC). This work was presented at the IV IEEE Workshop on Signal Processing Advances in Wireless Communication (SPAWC’03), Rome, Italy, June 2003. The review of this paper was coordinated by Prof. H. Leib.
PY - 2006/7
Y1 - 2006/7
N2 - In this paper, a new technique for simultaneous voice and multiclass data transmission over fading channels using adaptive hierarchical modulation is proposed. According to the link quality, the proposed scheme changes the constellation size as well as the priority parameters of the hierarchical signal constellations and assigns available subchannels (i.e., different bit positions) to different kinds of bits. Specifically, for very bad channel conditions, it only transmits voice with binary phase-shift keying (BPSK). As the channel condition improves, a variable-rate adaptive hierarchical M-ary quadrature amplitude modulation (M-QAM) is used to increase the data throughput. The voice bits are always transmitted in the lowest priority subchannel (i.e., the least significant bit (LSB) position) of the quadrature (Q) channel of the hierarchical M-QAM. The remaining (log2M - 1) subchannels, called data subchannels, are assigned to two different classes of data according to the selected priority parameters. Closed-form expressions as well as numerical results for outage probability, achievable spectral efficiency, and average bit error rate (BER) for voice and data transmission over Nakagami-m fading channels are presented. The adaptive techniques employing hybrid binary shift keying (BPSK)/M-ary AM (M-AM) and uniform M-QAM for simultaneous voice and two different classes of data transmission are also extended. Compared to the extended schemes, the new proposed scheme is spectrally more efficient for data transmission, while keeping the same outage probability for voice and data (both classes) as the scheme employing BPSK/M-AM. The new scheme also provides, as a by-product, a spectrally efficient way of transmitting voice and a single-class data.
AB - In this paper, a new technique for simultaneous voice and multiclass data transmission over fading channels using adaptive hierarchical modulation is proposed. According to the link quality, the proposed scheme changes the constellation size as well as the priority parameters of the hierarchical signal constellations and assigns available subchannels (i.e., different bit positions) to different kinds of bits. Specifically, for very bad channel conditions, it only transmits voice with binary phase-shift keying (BPSK). As the channel condition improves, a variable-rate adaptive hierarchical M-ary quadrature amplitude modulation (M-QAM) is used to increase the data throughput. The voice bits are always transmitted in the lowest priority subchannel (i.e., the least significant bit (LSB) position) of the quadrature (Q) channel of the hierarchical M-QAM. The remaining (log2M - 1) subchannels, called data subchannels, are assigned to two different classes of data according to the selected priority parameters. Closed-form expressions as well as numerical results for outage probability, achievable spectral efficiency, and average bit error rate (BER) for voice and data transmission over Nakagami-m fading channels are presented. The adaptive techniques employing hybrid binary shift keying (BPSK)/M-ary AM (M-AM) and uniform M-QAM for simultaneous voice and two different classes of data transmission are also extended. Compared to the extended schemes, the new proposed scheme is spectrally more efficient for data transmission, while keeping the same outage probability for voice and data (both classes) as the scheme employing BPSK/M-AM. The new scheme also provides, as a by-product, a spectrally efficient way of transmitting voice and a single-class data.
KW - Adaptive modulation
KW - Hierarchical constellations
KW - Multimedia communication
KW - Voice and data integration
UR - http://www.scopus.com/inward/record.url?scp=33746344673&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33746344673&partnerID=8YFLogxK
U2 - 10.1109/TVT.2005.863345
DO - 10.1109/TVT.2005.863345
M3 - Article
AN - SCOPUS:33746344673
SN - 0018-9545
VL - 55
SP - 1181
EP - 1194
JO - IEEE Transactions on Vehicular Technology
JF - IEEE Transactions on Vehicular Technology
IS - 4
ER -