在多輸入單輸出之色散通道環境下結合載波篩選之單載波頻域等化器

無線通訊系統在近幾年來被廣泛的研究，所需的資料傳輸速率也隨著時間不斷的再提升，因此多輸入- 多輸出(MIMO)系統被提出來增加資料傳輸速率，此系統是藉由傳送端和接收端的多根天線來增加資料傳輸速率。我們對於其中的多輸入-單輸出(MISO)系統詳加探討，此系統常利用於無線下行傳輸，即為配備多根天線的基地台(base station)傳輸資料到配備一根天線的無線用戶端。由於資料傳輸速率的增加，造成多重路徑的現象和符元間的相互干擾(ISI)變的更加嚴重，因此需要等化器。等化器通常在時域的情況下執行，然而伴隨著資料傳輸速率的增加，時域等化器(TDE)的複雜度也同樣大幅提升，為了克服這個問題，我們使用單載波頻域等化器(SC-FDE)。由於函數的摺積會隨著時域轉變成頻域後變成函數的相乘，因此頻域等化器所需的計算複雜度比時域等化器來的簡化許多。此外在本篇論文中將討論多輸入單輸出的系統，我們在傳送端提出一個新的程序，載波篩選(CS)，並且在接收端使用單載波頻域等化器經過色散的Nakagami-m 衰減通道，模擬結果顯示我們所提出的系統比其他沒有載波篩選或一般常見的系統改善許多，而且我們藉由不同的系統參數，去尋找降低系統錯誤率的極限值。此外, 有關頻域等化器，我們也將討論強制歸零(ZF) 和最小平方平均等化誤差(MMSE) 等化器這兩種等化器的特性。

關鍵字

載波篩選；強制歸零/最小平方平均等化誤差現性等化器；多輸入單輸出；衰減通道；單載波頻域等化器

並列摘要

The wireless communication systems have investigated over the recent years, the demand for data rates are more than before. Hence, the multiple input multiple output (MIMO) technique has been proposed to increase data rates by using several transmit and receive antennae. Of particular interset is multiple input single output (MISO) system where the base station (BS) equipped with multiple antennae sends its data to mobile units which possess a single receive antenna, which often employed in downlink mobile communications. However, in high data rate communications, the impacts of multipath propagation and intersymbol interference (ISI) have been increased and the resulting required equalizer. The equalizer is generally performed in time domain. However, with growing data rates the complexity of time domain equalizer (TDE) structures increases hugely. A process to overcome this problem is using single carrier frequency domain equalizer (SC-FDE). Since the convolution sequence in the time domain translate into product under frequency domain. Therefore, the FDE has lower computational complexity than TDE. Beside, in this thesis, under the MISO system, we propose a novel design, the carrier selection (CS) in the transmit-end, and the SC-FDE is applied at the receiver-end over dispersive Nakagami-m fading channels. Simulation results reveal that our proposed scheme is much greater than that without CS and other conventional coun- terparts and we find bit error rate (BER) performance limitation by various system parameters. Moreover, about the FDE, we will discuss the characterizations for two common strategies of the linear equalizer, zero-forcing (ZF) and minimum mean square error (MMSE).

並列關鍵字

Carrier selection ； SC-FDE fading channels ； , ZF/MMSE linear equalizer ； MISO

參考文獻

[4] R. W. Chang, “Synthesis of band-limited orthogonal signals for multichannel data transmission,” Bell Syst, Tech. J., vol. 45, pp. 1775–1796, Apr. 1966.

[5] T. Walzman and M. Schwartz, “Automatic equalization using the discrete frequency domain,” IEEE Trans. Inform. Theory, vol. 19, no. 1, pp. 59–68, Jan. 1973.

[6] D. Falconer, S. L. Ariyavisitakul, A. Benyamin-Seeyar, and B. Eidson, “Frequency domain equalization for single-carrier broadband wireless systems,” IEEE Commun. Mag., vol. 40, no.4, pp. 58–66, Apr. 2002.

[8] Air Interface for Fixed Broadband Wireless Access Systems Part A: Systems between 2 and 11 GHz, IEEE Std. 802.16ab-01/01, 2001.

[9] H. Sari, G. Karam, and I. Jeanclaude, “Frequency-Domain Equalization of Mobile Radio and Terrestrial Broadcast Channels,” Proc. GLOBECOM 1994, San Francisco, CA, Nov.-Dec. 1994, pp. 1–5.

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在多輸入單輸出之色散通道環境下結合載波篩選之單載波頻域等化器

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