Apparatuses and methods for measuring transmit signal power leaking into adjacent radio channels

1. An apparatus for a wireless communication system, comprising:

transmitter circuitry configured to generate a transmit signal on an assigned radio channel; and

transmitter feedback receiver circuitry coupled to the transmitter circuitry and configured to estimate an amount of transmit signal power that leaks into adjacent radio channels based on a fed back version of the transmit signal,

wherein the transmitter feedback receiver circuitry is configured to generate transmit signal power measurements during a first portion of a periodically recurring time slot and to measure the amount of transmit signal power that leaks into adjacent radio channels during a second portion of the time slot.

2. The apparatus of claim 1 , wherein the transmitter feedback receiver circuitry is configured to generate the transmit signal power measurements for adjusting the transmit power according to received transmit power control commands during a first mode of operation and to estimate the amount of transmit signal power that leaks into adjacent radio channels during a second mode of operation.

3. The apparatus of claim 1 , wherein the transmitter feedback receiver circuitry is configured to combine different measurements of the amount of transmit signal power that leaks into adjacent radio channels measured in different time slots.

4. The apparatus of claim 1 , wherein the transmitter feedback receiver circuitry is configured to measure the amount of transmit signal power that leaks into adjacent radio channels during a Radio Resource Control connected mode.

5. The apparatus of claim 1 , wherein the transmitter feedback receiver circuitry is configured to generate an adjacent channel leakage-power ratio spectrum of the fed back version of the transmit signal.

6. The apparatus of claim 1 ,

wherein the transmitter feedback receiver circuitry comprises Fourier transform circuitry configured to generate the adjacent channel leakage-power ratio spectrum based on a Fourier transform of the fed back version of the transmit signal, or

wherein the transmitter feedback receiver circuitry comprises filter circuitry configured to generate the adjacent channel leakage-power ratio spectrum based on filtering the fed back version of transmit signal with different bandpass-filters associated with respective adjacent radio channels.

7. The apparatus of claim 5 , wherein the transmitter feedback receiver circuitry is configured to scale the adjacent channel leakage-power ratio spectrum in accordance with a signal attenuation experienced by the fed back version of the transmit signal.

8. The apparatus of claim 1 , wherein the transmitter feedback receiver circuitry comprises an Analog-to-Digital Converter having a sampling rate of at least four times the bandwidth of the assigned radio channel.

9. The apparatus of claim 5 , wherein the adjacent channel leakage-power ratio spectrum is bandlimited in accordance with a sampling rate of the transmitter feedback receiver circuitry and wherein the transmitter feedback receiver circuitry is configured to increase a bandwidth of the adjacent channel leakage-power ratio spectrum by extrapolation.

10. The apparatus of claim 1 , wherein the transmitter circuitry and the transmitter feedback receiver circuitry are conformant with a first Radio Access Technology and wherein the apparatus further comprises transceiver circuitry conformant with at least one second Radio Access Technology.

11. The apparatus of claim 1 , wherein the transmitter circuitry and the transmitter feedback receiver circuitry are both coupled to the same controllable local oscillator.

12. A user equipment for a wireless communication system, comprising:

a first transceiver conformant with a first Radio Access Technology;

a second transceiver conformant with a second Radio Access Technology operating in one or more second radio channels adjacent to one or more first radio channels of the first Radio Access Technology,

wherein the second transceiver comprises

a transmitter configured to generate a transmit signal for an assigned second radio channel, and

a transmitter feedback receiver coupled to the transmitter and configured to generate an adjacent channel leakage-power ratio spectrum of a fed back version of the transmit signal,

wherein the transmitter feedback receiver is configured to generate transmit signal power measurements for adjusting a transmit power of the transmitter according to received transmit power control commands during a first portion of a periodically recurring time slot and to generate the adjacent channel leakage-power ratio spectrum during a second portion of the time slot.

13. The user equipment of claim 12 , wherein the transmitter feedback receiver is configured to scale the adjacent channel leakage-power ratio spectrum to compensate for a signal attenuation of the transmitter feedback receiver experienced by the fed back version of the transmit signal.

14. The user equipment of claim 12 , wherein the adjacent channel leakage-power ratio spectrum is bandlimited in accordance with a sampling rate of the transmitter feedback receiver and wherein the transmitter feedback receiver is configured to increase a bandwidth of the adjacent channel power leakage spectrum by extrapolation.

15. A method for measuring an adjacent channel leakage-power ratio spectrum of a transmit signal of a user equipment of a wireless communication system, the user equipment comprising a transmitter configured to generate the transmit signal and a transmitter feedback receiver coupled to the transmitter for feeding back the transmit signal, the method comprising:

during a first mode of operation of the transmitter feedback receiver, determining a power of the transmit signal based on a fed back transmit signal; and

during a second mode of operation of the transmitter feedback receiver, determining the adjacent channel leakage-power ratio spectrum of the transmit signal based on the fed back transmit signal,

in the first mode of operation of the transmitter feedback receiver, generating transmit signal power measurements for adjusting the transmit power according to received transmit power control commands during a first portion of a periodically recurring time slot; and

in the second mode of operation of the transmitter feedback receiver, measuring the adjacent channel leakage-power ratio spectrum during a second portion of the time slot.

16. The method of claim 15 , further comprising combining different measurements of the adjacent channel leakage-power ratio spectrum measured in different time slots.

17. The method of claim 15 , wherein the adjacent channel leakage-power ratio spectrum is measured during a Radio Resource Control connected mode of the user equipment.