01-01-2013, 10:33 AM
Multilevel Coupling Modulation for Multi-Resolution Multimedia Broadcast/Multicast Service in OFDM Systems
[attachment=45922]
Abstract
To meet the growing demand for multimedia services,
Multimedia Broadcast/Multicast Service (MBMS) was proposed
to enhance bandwidth efficiency in wireless communication
systems. Although MBMS supports multimedia streams with
several resolutions, streams with different resolutions are treated
as separate services and transmitted upon independent radio
resources, resulting in inefficient resource utilization. At the
receiver, some valuable information embedded in the higherresolution
channels is not utilized to enhance the reception of
the data stream in a lower resolution channel. In this work,
we propose a multilevel coupling modulation (MCM) scheme
aimed to improve the overall system throughput and to extend
the service coverage of the multi-resolution MBMS in orthogonal
frequency division multiplexing (OFDM) systems. The proposed
MCM scheme can fully utilize all the usable information conveyed
in different channels, thereby improving the receiving performance.
In addition, we derive the symbol error rates of the
proposed MCM scheme, in the AWGN and frequency-selective
fading channels, for performance evaluation. The analytical and
simulation results demonstrate that the proposed MCM scheme
can substantially enhance the receiving performance, service
accessibility and overall system throughput of multi-resolution
MBMS in OFDM systems.
INTRODUCTION
IN future-generation mobile communication systems, the
demand for multimedia streaming services is expected
to increase dramatically. To meet the demand, Multimedia
Broadcast/Multicast Service (MBMS) was proposed to
enhance the bandwidth efficiency of multimedia services.
MBMS is a unidirectional point-to-multipoint service that
supports multimedia streams with possibly several resolutions
from a single source to several destinations. By sharing the
same data stream, multiple interested users can acquire the
desired service simultaneously, thereby reducing the consumption
of radio resources. In the 3rd Generation Partnership
Project (3GPP) Release 6 [1].
SYSTEM MODEL AND MULTILEVEL COUPLING
MODULATION
A. System Model
Suppose that the number of sub-carriers available in the
transmission bandwidth is . As shown in Fig. 1, the MBMS
data stream is modulated by the proposed MCM scheme
(discussed in Section III), and then mapped to the sub-carriers
allocated for MBMS. Let X denote the aggregated frequencydomain
modulated data sequence in an OFDM symbol. By
applying an -point inverse fast Fourier transform (IFFT),
we obtain the time-domain OFDM symbol x for transmission.
After passing through the propagation chann.
MULTILEVEL COUPLING MODULATION FOR MBMS
A. Multilevel Coupling Modulation for Multi-resolution
MBMS
In MBMS, the most important issues are to provide a
reliable signal quality and to extend the service coverage.
However, in wireless multipath channels, the service quality
and service coverage may be severely degraded due to
selective-fading effects. To improve the received signal quality,
as well as the service quality and service coverage, we modify
the multi-resolution services of MBMS and propose the MCM
scheme for MBMS. Conceptually, the proposed MCM scheme
utilizes two distinct channels to convey the same information
for each service class. As a result, frequency-domain diversity
is introduced to efficiently resist selective-fading effects.
PERFORMANCE EVALUATION
In the simulation, we apply the system parameters used
in LTE systems. The sub-carrier spacing is 15 kHz and
the extended cyclic prefix (CP) is adopted. The number of
sub-carriers is assumed to be
[attachment=45922]
Abstract
To meet the growing demand for multimedia services,
Multimedia Broadcast/Multicast Service (MBMS) was proposed
to enhance bandwidth efficiency in wireless communication
systems. Although MBMS supports multimedia streams with
several resolutions, streams with different resolutions are treated
as separate services and transmitted upon independent radio
resources, resulting in inefficient resource utilization. At the
receiver, some valuable information embedded in the higherresolution
channels is not utilized to enhance the reception of
the data stream in a lower resolution channel. In this work,
we propose a multilevel coupling modulation (MCM) scheme
aimed to improve the overall system throughput and to extend
the service coverage of the multi-resolution MBMS in orthogonal
frequency division multiplexing (OFDM) systems. The proposed
MCM scheme can fully utilize all the usable information conveyed
in different channels, thereby improving the receiving performance.
In addition, we derive the symbol error rates of the
proposed MCM scheme, in the AWGN and frequency-selective
fading channels, for performance evaluation. The analytical and
simulation results demonstrate that the proposed MCM scheme
can substantially enhance the receiving performance, service
accessibility and overall system throughput of multi-resolution
MBMS in OFDM systems.
INTRODUCTION
IN future-generation mobile communication systems, the
demand for multimedia streaming services is expected
to increase dramatically. To meet the demand, Multimedia
Broadcast/Multicast Service (MBMS) was proposed to
enhance the bandwidth efficiency of multimedia services.
MBMS is a unidirectional point-to-multipoint service that
supports multimedia streams with possibly several resolutions
from a single source to several destinations. By sharing the
same data stream, multiple interested users can acquire the
desired service simultaneously, thereby reducing the consumption
of radio resources. In the 3rd Generation Partnership
Project (3GPP) Release 6 [1].
SYSTEM MODEL AND MULTILEVEL COUPLING
MODULATION
A. System Model
Suppose that the number of sub-carriers available in the
transmission bandwidth is . As shown in Fig. 1, the MBMS
data stream is modulated by the proposed MCM scheme
(discussed in Section III), and then mapped to the sub-carriers
allocated for MBMS. Let X denote the aggregated frequencydomain
modulated data sequence in an OFDM symbol. By
applying an -point inverse fast Fourier transform (IFFT),
we obtain the time-domain OFDM symbol x for transmission.
After passing through the propagation chann.
MULTILEVEL COUPLING MODULATION FOR MBMS
A. Multilevel Coupling Modulation for Multi-resolution
MBMS
In MBMS, the most important issues are to provide a
reliable signal quality and to extend the service coverage.
However, in wireless multipath channels, the service quality
and service coverage may be severely degraded due to
selective-fading effects. To improve the received signal quality,
as well as the service quality and service coverage, we modify
the multi-resolution services of MBMS and propose the MCM
scheme for MBMS. Conceptually, the proposed MCM scheme
utilizes two distinct channels to convey the same information
for each service class. As a result, frequency-domain diversity
is introduced to efficiently resist selective-fading effects.
PERFORMANCE EVALUATION
In the simulation, we apply the system parameters used
in LTE systems. The sub-carrier spacing is 15 kHz and
the extended cyclic prefix (CP) is adopted. The number of
sub-carriers is assumed to be