- タイトル
- 車車間通信におけるCSMAとCDMA slotted ALOHAのスループット評価
Throughput evaluation of CSMA and CDMA slotted ALOHA in inter-vehicle communication
- 著者
- 坂田篤則, 山里敬也, 岡田啓, 片山正昭
A.Sakata, T.Yamazato, H.Okada, M.Katayma
- 出典
- 信学技報RCS, no.RCS2007-55,
2007/08.
- キーワード
- inter-vehicle communication, CSMA, DS-CDMA, slotted ALOHA, spread ALOHA, simulation, throughput, hidden terminal, FDMA, capture effect
- 概要
- This paper evaluates the throughput performance of a carrier-sense multiple-access (CSMA) scheme that uses an orthogonal frequency multiple access physical layer and a CDMA slotted ALOHA scheme based on multiple-carrier CDMA (MC-CDMA) in inter-vehicle communication (IVC). In particular, we compare the throughputs in a situation where a hidden terminal is no longer negligible. We encounter such a situation in an intersection where two or more cars are crossing by. In a hidden terminal situation, the CSMA scheme ma degrade throughput. On the other hand, CDMA slotted ALOHA has a resistance to the hidden terminal situation as it can support simultaneous packets. However, the transmission data rate is much slow because of the spreading. Thus, the total throughput may not be as high as the CSMA based PFDM even in a hidden terminal situation. As a result, we show that the CSMA based OFDM system shows better total throughput than CDMA slotted ALOHA in all region. But, only the signal from nearest car can be received. On the contrary, CDMA slotted ALOHA can receive many packets simultaneously. This is much preferable feature for safety driving.
- 分類
- [COM]移動無線システム：車両間通信 (No.5663)