IST-2003-507581 WINNER D2.5 v1.0 Duplex ... - Celtic-Plus

WINNER D2.5 v1.0requirements are feasible, since UL and DL occur at different frequencies, and the isolation can beimproved with a duplex filter.For convenience, the requirements and their interpretation have been collected to Table 5-8. An additionalrequirement in FDD system is that the duplex filter must prevent the TX from disturbing the RX on thesame piece of equipment. Firstly, the isolation of the duplexer in the RX band must be sufficient tosuppress TX noise floor below RX noise floor. Secondly, duplex isolation in the TX band must beoptimised together with RX linearity to prevent TX leakage from blocking the receiver.Table 5-8: Equivalent RF requirements for an FDD systemRF Parameter WB NB Unit, CommentAP TX output power +43 +43 dBm, initial assumptionAP TX noise floor -100.3 -100.3 dBm/Hz, in DL band-155 -155 dBm/Hz, in UL band (with duplexer)-168 -168 dBm/Hz, from TX to RX in UL band (with duplexer)AP TX ACPR 60 69 dB, system requirement45 45 dB, relaxed specificationAP RX noise floor -89 -98 dBm, assuming NF = 6 dBAP RX max. power -48.5 -48.5 dBm, one channelAP RX blockers +43 +43 dBm, from TX within DL band (with duplexer)-48.5 -48.5 dBm, ACP, system requirement-52 -61 dBm, ACP, relaxed specification-45 -45 dBm, ACP2AP RX linearity, IIP2 +35 +35 dBm, UL band+171 +171 dBm, DL band (with duplexer)AP RX linearity, IIP3 -15 -15 dBm, UL band, relax specification+87 +87 dBm, DL band (with duplexer)AP Synthesizer As in Table 5-7.AP Duplex isolation 68 68 dB, TX-to-RX in DL bandMT TX output power +23 +23 dBm, initial assumptionMT TX noise floor -103.3 -103.3 dBm/Hz, in UL band-134 -134 dBm/Hz, in DL band (with duplexer)-165 -165 dBm/Hz, from TX to RX in DL band (with duplexer)MT TX ACPR 43 52 dB, system requirement39 39 dB, relaxed specification (still maybe too high)MT RX noise floor -86 -95 dBm, assuming NF = 9 dBMT RX max. power -28.5 -28.5 dBm, one channelMT RX blockers +23 +23 dBm, from TX within UL band (with duplexer)-28.5 -28.5 dBm, ACP, system requirement-45 -45 dBm, ACP, relaxed specification-32 -32 dBm, ACP2MT RX linearity, IIP2 +35 +35 dBm, DL band+131 +131 dBm, UL band (with duplexer)MT RX linearity, IIP3 -15 -15 dBm, DL band, relax specification+57 +57 dBm, UL band (with duplexer)MT Synthesizer As in Table 5-7.MT Duplex isolation 48 48 dB, TX-to-RX in UL bandInitial duplex filter requirements can be derived as follows. For AP output power +43 dBm, the TDDnoise floor requirement –100.5 dBm/Hz is already rather strict. Hence, the duplex filter must suppress theTX noise below RX noise floor –168 dBm/Hz, yielding isolation requirement 68 dB in the UL band.Assuming AP receiver linearity is sufficient to handle blocking power –25 dBm, the requirement for TXsignal suppression gives the same 68 dB. For MT, it seems necessary to reduce the TX noise floor bycircuit design to alleviate the isolation requirement in DL band. As to UL isolation, with output power+23 dBm and assuming again that from linearity perspective blocking powers –25 dBm are acceptable,the minimum UL band isolation requirement is 23+25 = 48 dB. The equivalent IIP2 and IIP3 can becalculated straightforwardly.Page 100 (121)