For multiple active spatial modulation (MASM) technique, this letter formulates the minimum number of transmit antennas $(N_{\mathrm {t}})$ and the required number of active RF chains ( $N_{\mathrm {a}}$ ) to support the following two statements. First, it is proven that MASM can achieve similar spectral efficiency to conventional spatial multiplexing (SMx) with smaller $N_{\mathrm {t}}$ and $N_{\mathrm {a}}$ , and less receive antennas ( $N_{\mathrm {r}}$ ). Secondly, for operation with the same $N_{\mathrm {t}}$ in both techniques, MASM is shown to achieve higher spectral efficiency while using fewer $N_{\mathrm {a}}$ and $N_{\mathrm {r}}$ . Furthermore, the low spectral efficiency and diversity tradeoff in MASM is highlighted, and a proposal of an enhanced MASM (E-MASM) technique is shown to achieve a better tradeoff between spectral efficiency and diversity as compared to SMx. In comparison to SMx and some prominent space modulation techniques, E-MASM is shown to achieve higher reliability, while MASM achieves superior spectral efficiency.

中文翻译：

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多重主动空间调制：不仅仅是空间复用的可能性

对于多主动空间调制 (MASM) 技术，这封信制定了最小发射天线数 $(N_{\mathrm {t}})$ 以及所需的有源射频链数量（ $N_{\mathrm {a}}$ ) 来支持以下两种说法。首先，证明 MASM 可以实现与传统空间复用 (SMx) 相似的频谱效率 $N_{\mathrm {t}}$ 和 $N_{\mathrm {a}}$ , 和更少的接收天线 ( $N_{\mathrm {r}}$ ）。其次，对于相同的操作 $N_{\mathrm {t}}$ 在这两种技术中，MASM 被证明可以实现更高的频谱效率，同时使用更少的 $N_{\mathrm {a}}$ 和 $N_{\mathrm {r}}$ . 此外，强调了 MASM 中的低频谱效率和多样性权衡，并且显示了增强 MASM（E-MASM）技术的提议，与 SMx 相比，可以在频谱效率和多样性之间实现更好的权衡。与 SMx 和一些突出的空间调制技术相比，E-MASM 显示出更高的可靠性，而 MASM 实现了卓越的频谱效率。