Dual Channel Reception

Abstract

There is provided a solution for simultaneous reception of dual channel transmission. The solution is based on applying a first and a second oscillating signals, mixing and adding in order to separate the in-phase and quadrature components of first and second signal from a combined radio frequency signal received as input.

1 . A method, comprising:
 receiving a combined radio frequency signal comprising a first and a second signals, the first and the second signals being on frequency bands of a first and a second channels, respectively, wherein the channels have different center frequencies;   dividing the combined radio frequency signal into an in-phase component and a quadrature component;   converting the in-phase and quadrature components of the combined radio frequency signal into digital form; and   separating in-phase and quadrature components of the first and the second signals from the in-phase and quadrature components of the combined radio frequency signal.   
     
     
         2 . The method according to  claim 1 , further comprising:
 mixing a first oscillating signal with the combined radio frequency signal to obtain the in-phase component of the combined radio frequency signal, the frequency of the first oscillating signal being in the middle of the center frequencies of the first and the second channel; and   mixing a quadrature of the first oscillating signal with the combined radio frequency signal to obtain the quadrature component of the combined radio frequency signal.   
     
     
         3 . The method according to  claim 1 , further comprising:
 mixing a second oscillating signal with the in-phase component and with the quadrature component of the combined radio frequency signal, the frequency of the second oscillating signal being a half of the difference between the center frequencies of the first and the second channels; and   mixing a quadrature of the second oscillating signal with the quadrature and in-phase components of the combined radio frequency signal.   
     
     
         4 . The method according to  claim 3 , further comprising:
 adding the second oscillating signal mixed with the in-phase component of the combined radio frequency signal to the quadrature of the second oscillating signal mixed with the quadrature component of the combined radio frequency signal to obtain the in-phase component of the first signal;   subtracting the quadrature of the second oscillating signal mixed with the quadrature component of the combined radio frequency signal from the second oscillating signal mixed with the in-phase component of the combined radio frequency signal to obtain the in-phase component of the second signal;   adding the second oscillating signal mixed with the quadrature component of the combined radio frequency signal to the quadrature of the second oscillating signal mixed with the in-phase component of the combined radio frequency signal to obtain the quadrature component of the second signal; and   subtracting the second oscillating signal mixed with the quadrature component of the combined radio frequency signal from the quadrature of the second oscillating signal mixed with the in-phase component of the combined radio frequency signal to obtain the quadrature component of the first signal.   
     
     
         5 . The method according to  claim 1 , further comprising:
 attenuating mirror frequencies of the first and the second signals.   
     
     
         6 . The method according to  claim 1 , wherein the center frequencies of the first and the second channels are separated by a channel bandwidth applied in the reception of the combined radio frequency signal. 
     
     
         7 . The method according to  claim 1 , further comprising: employing the method during high-speed downlink packet access (HSDPA) reception. 
     
     
         8 . An apparatus, comprising:
 an interface configured to receive a combined radio frequency signal comprising a first and a second signals, the first and the second signals being on frequency bands of a first and a second channels, respectively, wherein the channels have different center frequencies;   a processor configured to control:   a division of the combined radio frequency signal into an in-phase component and a quadrature component;   a converting of the in-phase and quadrature components of the combined radio frequency signal into digital form; and   a separation of in-phase and quadrature components of the first and the second signal from the in-phase and quadrature components of the combined radio frequency signal.   
     
     
         9 . The apparatus according to  claim 8 , wherein the processor is further configured to: control the mixing of a first oscillating signal with the combined radio frequency signal to obtain the in-phase component of the combined radio frequency signal, the frequency of the first oscillating signal being in the middle of the center frequencies of the first and the second channel; and control the mixing of a quadrature of the first oscillating signal with the combined radio frequency signal to obtain the quadrature component of the combined radio frequency signal. 
     
     
         10 . The apparatus according to  claim 8  wherein the processor is further configured to:
 control a mixing of a second oscillating signal with the in-phase component and with the quadrature component of the combined radio frequency signal, the frequency of the second oscillating signal being a half of the difference between the center frequencies of the first and the second channels; and 
 control a mixing of a quadrature of the second oscillating signal with the quadrature and in-phase components of the combined radio frequency signal. 
 
     
     
         11 . The apparatus according to  claim 10 , wherein the processor is further configured to:
 control an adding of the second oscillating signal mixed with the in-phase component of the combined radio frequency signal to the quadrature of the second oscillating signal mixed with the quadrature component of the combined radio frequency signal to obtain the in-phase component of the first signal;   control a subtracting of the quadrature of the second oscillating signal mixed with the quadrature component of the combined radio frequency signal from the second oscillating signal mixed with the in-phase component of the combined radio frequency signal to obtain the in-phase component of the second signal;   control an adding of the second oscillating signal mixed with the quadrature component of the combined radio frequency signal to the quadrature of the second oscillating signal mixed with the in-phase component of the combined radio frequency signal to obtain the quadrature component of the second signal; and   control a subtracting of the second oscillating signal mixed with the quadrature component of the combined radio frequency signal from the quadrature of the second oscillating signal mixed with the in-phase component of the combined radio frequency signal to obtain the quadrature component of the first signal.   
     
     
         12 . The apparatus according to  claim 8 , wherein the processor is further configured to:
 control an attenuating of mirror frequencies of the first and the second signal.   
     
     
         13 . The apparatus according to  claim 8 , wherein the center frequencies of the first and the second channels are separated by a channel bandwidth applied in the reception of the combined radio frequency signal. 
     
     
         14 . The apparatus according to  claim 8 , wherein the apparatus is employed during high-speed downlink packet access (HSDPA) reception. 
     
     
         15 . An apparatus, comprising:
 an interface configured to receive a combined radio frequency signal comprising a first and a second signals, the first and the second signals being on frequency bands of a first and a second channels, respectively, wherein the channels have different center frequencies;   a processor configured to divide the combined radio frequency signal into an in-phase component and a quadrature component;   a converter configured to convert of the in-phase and quadrature components of the combined radio frequency signal into digital form; and   the processor is further configured to separate in-phase and quadrature components of the first and the second signals from the in-phase and quadrature components of the combined radio frequency signal.   
     
     
         16 . The apparatus according to  claim 15 , further comprising: a first mixer configured to mix a first oscillating signal with the combined radio frequency signal to obtain the in-phase component of the combined radio frequency signal, the frequency of the first oscillating signal being in the middle of the center frequencies of the first and the second channel; and a second mixer configured to mix a quadrature of the first oscillating signal with the combined radio frequency signal to obtain the quadrature component of the combined radio frequency signal. 
     
     
         17 . The apparatus according to  claim 15 , further comprising:
 a third mixer configured to mix a second oscillating signal with the in-phase component of the combined radio frequency signal, the frequency of the second oscillating signal being a half of the difference between the center frequencies of the first and the second channels;   a fourth mixer configured to mix the second oscillating signal with the quadrature component of the combined radio frequency signal;   a fifth mixer configured to mix a quadrature of the second oscillating signal with the quadrature component of the combined radio frequency signal;   a sixth mixer configured to mix the quadrature of the second oscillating signal with the in-phase component of the combined radio frequency signal.   
     
     
         18 . The apparatus according to  claim 14 , further comprising:
 an adder configured to add the outputs of the third and the fifth mixer to obtain the in-phase component of the first signal;   a subtractor configured to subtract the output of the fifth mixer from the output of the third mixer to obtain the in-phase component of the second signal;   an adder configured to add the output of the fourth and the sixth mixer to obtain the quadrature component of the second signal; and   a subtractor configured to subtract the output of the fourth mixer from the output of the sixth mixer to obtain the quadrature component of the first signal.   
     
     
         19 . The apparatus according to  claim 15 , wherein the processor is further configured to attenuate mirror frequencies of the first and the second signals. 
     
     
         20 . The apparatus according to  claim 15 , wherein the center frequencies of the first and the second channels are separated by a channel bandwidth applied in the reception of the combined radio frequency signal. 
     
     
         21 . The apparatus according to  claim 15 , wherein the apparatus is employed during high-speed downlink packet access (HSDPA) reception. 
     
     
         22 . An apparatus, comprising:
 means for receiving a combined radio frequency signal comprising a first and a second signals, the first and the second signals being on frequency bands of a first and a second channels, respectively, wherein the channels have different center frequencies;   means for dividing the combined radio frequency signal into an in-phase component and a quadrature component;   means for converting the in-phase and quadrature components of the combined radio frequency signal into digital form; and   means for separating in-phase and quadrature components of the first and the second signals from the in-phase and quadrature components of the combined radio frequency signal.   
     
     
         23 . A computer program product, embodied on a non-transitory computer-readable storage medium and comprising a program code which, when run on a processor, executes the method comprising:
 controlling a reception of a combined radio frequency signal comprising a first and a second signals, the first and the second signals being on frequency bands of a first and a second channels, respectively, wherein the channels have different center frequencies;   dividing the combined radio frequency signal into an in-phase component and a quadrature component;   converting the in-phase and quadrature components of the combined radio frequency signal into digital form; and   separating in-phase and quadrature components of the first and the second signals from the in-phase and quadrature components of the combined radio frequency signal.