A signal interface unit for a distributed antenna system includes a channelized radio carrier interface configured to communicate an uplink channelized radio carrier for a radio frequency carrier to a channelized radio carrier base station interface; an antenna side interface configured to receive an uplink digitized radio frequency signal from the distributed antenna system communicatively coupled to the antenna side interface, wherein the uplink digitized radio frequency signal includes baseband data having bits; and a signal conversion module communicatively coupled between the channelized radio carrier interface and the antenna side interface and configured to convert between the uplink digitized radio frequency signal and the uplink channelized radio carrier at least in part by performing an adjustment of the bits included in the baseband data for the uplink digitized radio frequency signal received from the distributed antenna system to comply with requirements of the channelized radio carrier base station interface.

A signal interface unit for a distributed antenna system (DAS) includes a channelized radio carrier interface configured to receive a downlink channelized radio carrier for a radio frequency carrier from a channelized radio carrier base station interface; an antenna side interface configured to communicate a downlink digitized radio frequency signal from the antenna side interface to the DAS communicatively coupled to the antenna side interface; and a signal conversion module communicatively coupled between the channelized radio carrier interface and the antenna side interface and configured to convert between the downlink channelized radio carrier and the downlink digitized radio frequency signal at least in part by adjusting at least one downlink attribute of the downlink digitized radio frequency signal communicated to the DAS based on requirements of the channelized radio carrier base station interface to cause the DAS to appear as a remote radio head to the channelized radio carrier interface.

An embodiment of the disclosed MIMO transceiver uses a single master clock to generate (i) the sampling-clock signals for the analog-to-digital and digital-to-analog converters and (ii) the multiple electrical local-oscillator signals that are used in various channels of the transceiver's analog down- and up-converters to translate signals between the corresponding intermediate-frequency and RF bands. The MIMO transceiver may employ a plurality of interconnected frequency dividers configured to variously divide the master-clock frequency to generate the sampling-clock signals and the multiple local-oscillator signals in a manner that causes these signals to have different respective frequencies. In embodiments designed for operating in the mmW band, the MIMO transceiver may also employ a frequency multiplier configured to multiply the master-clock frequency to generate an additional local-oscillator signal for translating signals between the mmW and RF bands.

An embodiment of the disclosed MIMO transceiver uses a single master clock to generate (i) the sampling-clock signals for the analog-to-digital and digital-to-analog converters and (ii) the multiple electrical local-oscillator signals that are used in various channels of the transceiver's analog down- and up-converters to translate signals between the corresponding intermediate-frequency and RF bands. The MIMO transceiver may employ a plurality of interconnected frequency dividers configured to variously divide the master-clock frequency to generate the sampling-clock signals and the multiple local-oscillator signals in a manner that causes these signals to have different respective frequencies. In embodiments designed for operating in the mmW band, the MIMO transceiver may also employ a frequency multiplier configured to multiply the master-clock frequency to generate an additional local-oscillator signal for translating signals between the mmW and RF bands.

A signal interface unit for a distributed antenna system (DAS) includes a channelized radio carrier interface configured to receive a downlink channelized radio carrier for a radio frequency carrier from a channelized radio carrier base station interface; an antenna side interface configured to communicate a downlink digitized radio frequency signal from the antenna side interface to the DAS communicatively coupled to the antenna side interface; and a signal conversion module communicatively coupled between the channelized radio carrier interface and the antenna side interface and configured to convert between the downlink channelized radio carrier and the downlink digitized radio frequency signal at least in part by adjusting at least one downlink attribute of the downlink digitized radio frequency signal communicated to the DAS based on requirements of the channelized radio carrier base station interface to cause the DAS to appear as a remote radio head to the channelized radio carrier interface.

An IFoF scheme optical transmission system according to the present disclosure technology includes a transmission-side digital signal processor including a system number compressor; and a parameter updater, the system number compressor compressing n digital data streams into m digital data streams, m being smaller than n, and the parameter updater updating a parameter used by the system number compressor by referring to a value of an evaluation function using a signal string handled by the transmission-side digital signal processor as an argument.

An IFoF scheme optical transmission system according to the present disclosure technology includes a transmission-side digital signal processor including a system number compressor; and a parameter updater, the system number compressor compressing n digital data streams into m digital data streams, m being smaller than n, and the parameter updater updating a parameter used by the system number compressor by referring to a value of an evaluation function using a signal string handled by the transmission-side digital signal processor as an argument.