Adaptive harmonic rejection receiving device and method

1. An adaptive harmonic rejection (HR) receiving device, comprising:

a low noise amplification module;

at least one harmonic rejection (HR) mixer;

at least one non-harmonic rejection (NHR) mixer; and

a control device, wherein a received signal first goes into low noise amplification module, and then passes through the at least one HR mixer or the at least one NHR mixer; the control device detects a receiving signal strength index (RSSI) after the received signal passes through the at least one HR mixer or the at least one NHR mixer, and selects an NHR mixer or an appropriate HR mixer for the received signal according to the detecting result.

2. The adaptive HR receiving device according to claim 1 , wherein the control device comprises: a transimpedance amplifier (TIA), a low pass filter (LPF) connected to the TIA, a programmable gain amplifier (PGA) connected to the LPF, a ADC (analog to digital converter) connected to the PGA, and a digital signal processor (DSP) module connected to the ADC (analog to digital converter).

3. The adaptive HR receiving device according to claim 2 , wherein the low noise amplification module is a low noise transconductance amplifier (LNTA), and the received signal is converted to a current signal after passing through the LNTA.

4. The adaptive HR receiving device according to claim 3 , wherein the current signal is converted to a voltage signal at an output of the TIA.

5. The adaptive HR receiving device according to claim 3 , wherein the LNTA comprises a load, and the load of LNTA is divided into several bands; the load of each band is formed of an L-C radio frequency filter and a switch; each band covers part of the input frequency range, and only one band is enabled during the same time period.

6. The adaptive HR receiving device according to claim 5 , wherein the LNTA comprises a plurality of band selecting (BS) switches; the BS switches' output connects to both of the at least one HR mixers inputs and the NHR mixer inputs; the BS switches' input connects to load circuit of the specific load respectively; and only one BS switch operates in on mode during the same time period.

7. The adaptive HR receiving device according to claim 6 , Wherein there is a mixer gain control stage inserted between the BS switches output and the NHR or HR mixer input.

8. The adaptive HR receiving device according to claim 2 , wherein the digital signal processor (DSP) module comprises:

a calculation unit, for calculating frequency of each harmonic channel of the received signal;

a measurement unit, for measuring each harmonic channel RSSI one by one according to the frequency of each harmonic channel calculated by the calculation unit, and for measuring an RSSI of a certain received signal path; and

a selection unit, for selecting the NHR mixer or an appropriate HR mixer for the received signal according to each harmonic channel RSSI measured and RSSI of the desired received signal path.

9. The adaptive HR receiving device according to claim 8 , wherein the DSP module further comprises an initial judgment unit, for performing initial judgment on the signal to decide whether it needs harmonic rejection, and the judgment policy is as follows: if RF input frequency>i*max input frequency, then it does not need harmonic rejection and an NHR mixer is directly selected for the received signal.

10. The adaptive HR receiving device according to claim 9 , wherein the selection unit adopted a policy to select an HR mixer or an NHR mixer for the received signal as follows: if RSSI of desired channel of the received signal minus RSSI of harmonic channel>HR_threshold, then do not need harmonic rejection and a NHR mixer is selected for the received signal; otherwise, need harmonic rejection and a HR mixer is selected for the received signal; wherein the HR_threshold is the threshold for HR operation.

11. An adaptive harmonic rejection receiving method, comprising:

calculation: calculating frequency of each harmonic channel of the received signal;

measurement: after the received signal passes through a low noise amplification, a non-harmonic rejection (NHR) frequency mixer, and HR mixers, selectively measuring a Received Signal Strength Indicator (RSSI) at an output of a signal path of an HR mixer or NHR mixer corresponding to the frequency of each harmonic order according to the frequency of each harmonic order of the received signal, and measuring an RSSI on a signal path corresponding to the frequency of the received signal; and

selection: selecting an NHR mixer or an appropriate HR mixer for the received signal.

12. The adaptive HR receiving method according to claim 11 , wherein the method further comprises an initial judgment step before the calculation step used to judge whether the received signal requires HR, and if HR is not required, an NHR signal path is directly selected for the received signal.

13. The adaptive HR receiving method according to claim 12 , wherein in the initial judgment step, a policy for judging whether the received signal requires HR is as follows: if RF input frequency>i*max input frequency, then it does not need harmonic rejection.

14. The adaptive HR receiving method according to claim 13 , wherein the value of the coefficient i is ½ or ⅓.

15. The adaptive HR receiving method according to claim 12 , wherein in the measurement step, a policy for selective measurement is as follows:

comparing the frequency of each harmonic order with a maximum input frequency one by one, if channel frequency>j*max input frequency, using NHR mixer and measuring RSSI of the received signal after passing through the NHR mixer; otherwise, if channel frequency<j*max input frequency, using HR mixer and measuring RSSI of the received signal after passing through the HR mixer.

16. The adaptive HR receiving method according to claim 15 , wherein, the value of j is ½ or ⅓.

17. The adaptive HR receiving method according to claim 12 , wherein in the selection step, a policy for selecting an HR mixer or an NHR mixer for the received signal is as follows:

if RSSI of desired received signal channel minus RSSI of harmonic channel>HR_threshold, then a non-harmonic rejection mixer is needed; otherwise, a harmonic rejection mixer is needed.