| 词条 | TC-PAM |
| 释义 |
Trellis-coded pulse-amplitude modulation (TC-PAM) is the modulation format that is used in HDSL2 and G.SHDSL. It is a variant of trellis coded modulation (TCM) which uses a one-dimensional pulse-amplitude modulation (PAM) symbol space, as opposed to a two-dimensional quadrature amplitude modulation (QAM) symbol space.[1] Compared to the 2B1Q scheme used in the older HDSL and SDSL standards, TC-PAM improves range at a given bit-rate and provides enhanced spectral compatibility with ADSL. TC-PAM is also known as 4B1H, because it uses 16 levels to represents a 4 digit binary, 4 Binary 1 Hexadecimal. References1. ^Johannes Huber. "Multilevel-Codes: Distance Profiles and Channel Capacity". {{Bit-encoding}}{{DEFAULTSORT:Tc-Pam}}{{telecomm-stub}} 1 : Quantized radio modulation modes |
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