Method and apparatus for improving the performance of MIMO wireless systems
Method and apparatus for efficiently providing DC power enhancement to power amplifiers each of which being arranged in a MIMO system, by suing an enhancement circuitry with a plurality of inputs and outputs. Each input has a corresponding DC enhancement output that is connected to a DC enhancement input of a power amplifier. The DC enhancement output becomes operative whenever the amplitude of the corresponding input signal exceeds a predetermined threshold. The envelope of a plurality of input signals is sampled by sampling circuitries and the sampled envelopes are fed into a summation circuitry, in which they are summed. Whenever one of the sampled envelopes exceeds the threshold, a DC enhancement power is simultaneously provided to all DC enhancement inputs of all power amplifiers.
1. A method for efficiently providing DC power enhancement to power amplifiers each of which being arranged in a MIMO system, comprising:
a) providing an enhancement circuitry having a plurality of inputs and outputs, such that each input has a corresponding DC enhancement output, connected to a DC enhancement input of a power amplifier and being operative whenever the amplitude of the corresponding input signal exceeds a predetermined threshold;
b) sampling the envelope of a plurality of input signals by sampling circuitries;
c) feeding the sampled envelopes into a summation circuitry and summing said sampled envelopes; and
d) whenever one of said sampled envelopes exceeds said threshold, simultaneously providing a DC enhancement power to all DC enhancement inputs of all power amplifiers.
2. A method according to claim 1 , wherein the summation circuitry includes an open collector configuration.
3. A method according to claim 1 , further comprising matching the input and the output of two or more amplifiers, thereby causing said amplifiers to be unconditionally stable under any level of input signal.
4. Apparatus for efficiently providing DC power enhancement to power amplifiers each of which being arranged in a MIMO system, comprising:
e) an enhancement circuitry having a plurality of inputs and outputs, such that each input has a corresponding DC enhancement output, connected to a DC enhancement input of a power amplifier and being operative whenever the amplitude of the corresponding input signal exceeds a predetermined threshold;
f) sampling circuitry for sampling the envelope of a plurality of input signals by sampling circuitries; and
g) a summation circuitry into which the sampled envelopes are fed, for summing said sampled envelopes,
wherein said enhancement circuitry simultaneously provides a DC enhancement power to all DC enhancement inputs of all power amplifiers, whenever one of said sampled envelopes exceeds said threshold.
5. Apparatus according to claim 3 , in which the summation circuitry includes an open collector configuration.
6. Apparatus according to claim 3 , further comprising matching circuitry for matching the input and the output of two or more amplifiers to be unconditionally stable under any level of input signal.