Dual Band Digital GSM 900/1800 Repeater

Hi experts,

I am trying to design a dual band digital GSM repeater operating at 900 & 1800 MHz bands.

It should have options of choosing at-least 3 sub-bands each totaling 25 MHz for GSM 900 & 60 MHz for GSM 1800 MHz band.

It would comprise of mixers, LOs, Filters, ADC/DAC, DDC/DUC which will facilitate flexible sub-band selectivity.

Could someone please tell me how do I go 'bout it...

I have some basic doubts:
1. Which architecture shall I follow:
a. Heterodyne Tx/Rx.
b. Homodyne Tx/Rx.
c. Heterodyne Rx & Homodyne Tx.
d. Homodyne Rx & Heterodyne Tx.


2. I understand using a Homodyne Tx/Rx shall have significant cost benefits but does it have any set-backs making it unsuitable for repeater design.

Thanks in advance
John Nicholas