Method and apparatus for operating co-located transceivers on the same frequency band

A method for operating a small cell and a backhaul wireless modem, comprising:

• transmitting from the small cell on a first sub-band, where the small cell comprises a first receiver front end and a first transmitter front end, where the first transmitter front end comprise a first selective filter, where the first receiver front end comprises a second selective filter, where each of the first selective filter and the second selective filter comprises a first filter coupled to a first switch, where the first filter comprises two passbands, where one of the two passbands is in a first sub-band, and where the first switch in each of the first selective filter and the second selective filter is set to select the first sub-band;
• only when the small cell is transmitting, receiving on the backhaul wireless modem, coupled to the small cell, on a second sub-band in the one frequency band and adjacent to the first sub-band, where the backhaul wireless modem comprises a second receiver front end and a second transmitter front end, where the second transmitter front end comprises a third selective filter, where the second receiver front end comprises a fourth selective filter, where each of the third selective filter and the fourth selective filter comprises a second filter coupled to a second switch, where the second filter comprises two passbands, where one of the two passbands is in a second sub-band, and where the second switch in each of the third selective filter and the fourth selective filter is set to select the second sub-band;
• receiving on the small cell on the first sub-band;
• only when the small cell is receiving, transmitting from the backhaul wireless modem on the second sub-band;
• wherein the small cell is configured to only transmit and receive in the first sub-band of the frequency band when the backhaul wireless modem is respectively receiving and transmitting in the second sub-band of the frequency band;
• and
• wherein the backhaul wireless modem is configured to only transmit and receive in the second sub-band when the small cell is respectively receiving and transmitting the first sub-band.

A communications system operating in a frequency band, comprising:

• a small cell with selective filtering comprising:
• a first transceiver;
• at least one first transmitter front end with selective filtering coupled to the first transceiver;
• wherein each of the at least one first transmitter front end with selective filtering comprises:
• a first power amplifier coupled the first transceiver;
• a first low pass filter coupled to the first power amplifier;
• and
• a first selective filter coupled to the first low pass filter;
• wherein the first selective filter comprises:
• a first duplexer having three ports;
• a first single pole double pole (SPDT) switch having two terminals, a common terminal, and a control terminal;
• wherein two ports of the first duplexer are coupled to two terminals of the first SPDT switch;
• and
• wherein the first SPDT switch is configured to select one of the two filters of the first duplexer based upon a signal applied to the control terminal of the first SPDT switch;
• at least one first receiver front end with selective filtering coupled to the first transceiver;
• wherein each receiver front end with selective filtering comprises:
• a second selective filter;
• and
• a first low noise amplifier coupled to the second selective filter;
• wherein the second selective filter comprises:
• a second duplexer having three ports and two filters;
• a second single pole double pole (SPDT) switch having two terminals, a common terminal, and a control terminal;
• wherein two ports of the second duplexer are coupled to two terminals of the second SPDT switch;
• and
• wherein the second SPDT switch is configured to select one of the two filters of the second duplexer based upon a signal applied to the control terminal of the second SPDT switch;
• a backhaul wireless modem with selective filtering, coupled to and proximate to the small cell, comprising:
• a second transceiver;
• at least one second transmitter front end with selective filtering coupled to the second transceiver;
• wherein each of the at least one second transmitter front end with selective filtering comprises:
• a second power amplifier coupled the second transceiver;
• a second low pass filter coupled to the power amplifier;
• and
• a third selective filter coupled to the second low pass filter;
• wherein the third selective filter comprises:
• a third duplexer having three ports and two filters;
• a third single pole double pole (SPDT) switch having two terminals, a common terminal, and a control terminal;
• wherein two ports of the third duplexer are coupled to two terminals of the third SPDT switch;
• and
• wherein the third SPDT switch is configured to select one of the two filters of the third duplexer based upon a signal applied to the control terminal of the third SPDT switch;
• at least one first receiver front end with selective filtering coupled to the first transceiver;
• wherein each of the at least one receiver front end with selective filtering comprises:
• a fourth selective filter;
• and
• a second low noise amplifier coupled to the fourth selective filter;
• wherein the fourth selective filter comprises
• a fourth duplexer having three ports and two filters;
• a fourth single pole double pole (SPDT) switch having two terminals, a common terminal, and a control terminal;
• wherein two ports of the fourth duplexer are coupled to two terminals of the fourth SPDT switch;
• and
• wherein the fourth SPDT switch is configured to select one of the two filters of the fourth duplexer based upon a signal applied to the control terminal of the fourth SPDT switch;
• and
• wherein the small cell with selective filtering is configured to transmit and receive in a first sub-band of the frequency band when the backhaul wireless modem with selective filtering is respectively receiving and transmitting a second sub-band of the frequency band;
• wherein the backhaul wireless modem with selective filtering is configured to transmit and receive in the second sub-band when the small cell with selective filtering is respectively receiving and transmitting the first sub-band;
• and
• wherein the first sub-band and the second sub-band are adjacent.