## 1 Introduction  
Ever since the multimedia broadcast multicast service (MBMS) was introduced in the 3 rd Generation Partnership Project (3 GPP), continuing work on the multicast transmission has been done and its importance is growing in the fifth generation (5G) cellular networks [1]. The use cases of multicast transmission have been enlarged from mobile TV and public safety to multimedia and entertainment, internet of things (IoT), automotive, public warning, airborne communications, mmWave communications and so on [2; 3]. To meet the stringent latency and reliability requirements in vehicular-to-everything (V2X), many studies have been done so far; for example, a low-latency multicast scheme in Reference [4], reliability improvement via user equipment (UE) acknowledgementfeedback for hybrid automatic repeat request (HARQ) in Reference [5] and evaluation of latency and packet reception ratio in V2X scenarios in Reference [6]. Multicast transmission is an attractive solution when a large number of users receive the same content in a wide area, for example, as with mobile TV. Allocating an individual unicast channel for each user in a multicast service wastes resources, since the same content is delivered through different unicast channels. Obviously, as more people use the multicast service, multicast transmission consumes fewer resources than unicast transmission, since it uses a single, common multicast channel instead of as many unicast channels as the number of users. Unlike unicast transmission, however, _conventional_ multicast transmission receives no feedback from users on channel quality information and therefore, the well-known _link adaptation_ cannot be applied, that is, modulation level and coding rate are fixed [7]. Therefore, bandwidth is determined conservatively so that even the user having the worst channel quality, herein called _the worst user_, can obtain a target multicast rate. This conservative resource allocation, however, may consume excessive resources since the minimum required bandwidth varies depending on the channel quality of the worst user. For example, resources can be conservatively allocated so that even the user located at the cell edge can achieve the target multicast rate. Since the users are placed randomly within a cell, most of them lie closer to the base station (BS) and the worst user in a multicast service is located at the cell edge with a very low probability. Therefore, the worst user experiences better channel quality in most cases than when it is at the cell edge, which, in turn, requires fewer resources. Therefore, the worst user experiences better channel quality, which in turn, requires fewer resources. In Reference [8], to overcome this problem, unicast channels were additionally provided, in addition to the multicast channel, for users having poor channel quality. However, channel quality feedback is still not supported for the multicast channel and therefore, the multicast channel is not adaptive to the channel variations of the users. Recently, for group communications in public safety networks and for geographical information sharing in social networks, multicast transmission has been targeted at fewer users in a relatively small area. In this case, the conventional multicast transmission scheme is no longer efficient, since it is designed for multicast transmission over a wide area where a large number of BSs are involved. Thus, a single-cell multicast transmission scheme has been studied by the 3 GPP [9; 10; 11]. A representative one is the so-called _single-cell point-to-multipoint_ (SC-PTM) scheme. The extended cyclic prefix (CP) is a special CP with a longer duration than the normal CP, which is designed to mitigate the inter-symbol interference due to the longer-delayed signals from neighboring cells in a multi-cell operation of the conventional multicast transmission scheme [2]. Owing to single-cell operation, however, the single-cell multicast scheme is able to use the normal CP, that is, the same frame structure as in the unicast transmission.