Modulation including zero-power states in 5G and 6G
Modulation schemes are disclosed that include one or more zero-power modulation states, in which the transmitter briefly emits zero or very low signal for one resource element of a message in 5G or 6G networking. In phase-modulated examples such as QPSK, an additional zero-power state can provide higher information density and shorter message sizes. In pulse-amplitude modulated schemes, the additional states can have zero power in one or both branches, thereby providing multiple additional modulation options. The receiver can readily detect and interpret the zero-power modulation states. Messages transmitted including the zero-power modulation states are generally shorter (in time or in bandwidth) due to the higher information density, and involve substantially lower energy expenditure because the message size is smaller, and because some of the states have zero or very low transmission power. Receivers also can benefit from the smaller size messages. Special zero-power states can be reserved for indicating the start and end of each message, for example.
1. A method for modulating a wireless message comprising a plurality of message elements, each message element modulated according to a modulation scheme comprising one or more amplitude modulation levels or one or more phase modulation levels, the method comprising:
transmitting a first message element of the plurality of message elements, the first message element modulated with a first amplitude value; and
transmitting a second message element of the plurality of message elements, the second message element modulated with an amplitude of substantially zero, wherein substantially zero comprises less than a predetermined limit of the first amplitude value, the predetermined limit comprising 1% or 2% or 5% or 10% of the first amplitude value.
2. The method of claim 1 , wherein the message is transmitted according to 5G or 6G technology.
3. The method of claim 1 , wherein:
the modulation scheme comprises a first state, a second state, and a third state;
the first state comprises an amplitude of a first amplitude modulation level and a phase of a first phase modulation level;
the second state comprises an amplitude equal to the first amplitude modulation level and a phase equal to 180 degrees plus the first phase modulation level; and
the third state comprises an amplitude of zero or substantially zero.
4. The method of claim 1 , wherein:
the modulation scheme comprises pulse-amplitude modulation “PAM”;
each message element comprises a sum of an I-branch signal and a Q-branch signal, the Q-branch signal phase-shifted by 90 degrees relative to the I-branch signal;
a particular message element comprises a particular I-branch signal plus a particular Q-branch signal; and
either the particular I-branch signal or the particular Q-branch signal has zero or substantially zero amplitude.
5. The method of claim 4 , wherein:
the modulation scheme comprises five branch amplitude levels comprising −3, −1, 0, +1, and +3 amplitude units respectively.
6. The method of claim 4 , wherein:
the modulation scheme comprises five branch amplitude levels comprising −4, −2, 0, +2, and +4 amplitude units respectively.
7. The method of claim 4 , wherein:
the modulation scheme further comprises a central modulation state comprising a central I-branch signal plus a central Q-branch signal;
the central I-branch signal has zero or substantially zero amplitude, and the central Q-branch signal has zero or substantially zero amplitude.
8. The method of claim 7 , wherein:
a first resource element, modulated according to the central modulation state, is positioned before the message, and a second resource element, modulated according to the central modulation state, is positioned after the message.
9. The method of claim 1 , wherein:
a first demodulation reference is positioned before the message, and a second demodulation reference is positioned after the message.
10. The method of claim 9 , wherein:
each demodulation reference of the first and second demodulation reference comprises a maximum amplitude of the modulation scheme, or a minimum amplitude of the modulation scheme, or both.
11. The method of claim 1 , further comprising:
receiving an incoming message comprising incoming message elements;
determining that at least one of the incoming message elements has a third amplitude level;
determining that at least one of the incoming message elements has a fourth amplitude level;
wherein a magnitude of the fourth amplitude level is at most 1% of a magnitude of the third amplitude level.
12. The method of claim 11 , further comprising:
determining that a first incoming message element is amplitude modulated according to the third amplitude level and phase modulated at 0 degrees, and demodulating the first incoming message element as the first state;
determining that a second incoming message element is amplitude modulated according to the third amplitude level and phase modulated at 180 degrees, and demodulating the second incoming message element as the second state; and
determining that a third incoming message element is amplitude modulated according to the fourth amplitude level, and demodulating the third incoming message element as the third state.
13. Non-transitory computer-readable media in a base station of a wireless network, the media containing instructions that when executed in a computing environment cause a method to be performed, the method comprising:
modulating, according to a modulation scheme, each message element of a message comprising message elements; wherein:
the modulation scheme comprises amplitude modulation including at least a first amplitude level and a second amplitude level, wherein the second amplitude level is substantially zero;
wherein substantially zero comprises a magnitude of the second amplitude level is at most a predetermined fraction of a magnitude of the first amplitude level; and
wherein the predetermined fraction is in the list of 1%, 2%, 5%, and 10%.
14. The media of claim 13 , the method further comprising:
wherein the message includes a leading message element at the start of the message and a trailing message element at the end of the message;
modulating the leading and trailing message elements of the message according to the first amplitude level; and
modulating at least one message element, between the leading and trailing message elements, according to the second amplitude level.
15. The media of claim 13 , wherein:
the modulation scheme comprises a first, second, and third modulation state;
the first modulation state is amplitude modulated according to the first amplitude level and is phase modulated at zero degrees;
the second modulation state is amplitude modulated according to the first amplitude level and is phase modulated at 180 degrees; and
the third modulation state is amplitude modulated according to the second amplitude level.
16. The media of claim 13 , the method further comprising:
receiving, from a user device in signal communication with the base station, an uplink demodulation reference and an uplink message, the uplink demodulation reference and the uplink message modulated according to the modulation scheme;
measuring, according to a demodulation reference, a third amplitude value;
determining that at least one message element of the uplink message is amplitude modulated according to the third amplitude value;
determining that at least one message element of the uplink message is amplitude modulated according to a fourth amplitude level which is at most the predetermined fraction of a magnitude of the third amplitude level.
17. A wireless user device, in signal communication with a base station of a wireless network, the user device configured to:
receive a demodulation reference and a message, the message comprising message elements, the demodulation reference and the message modulated according to a modulation scheme comprising amplitude modulation;
determine, according to the demodulation reference, a first amplitude level;
determine that a first message element of the message comprising message elements is amplitude modulated according to the first amplitude level; and
determine that a second message element is amplitude modulated according to a second amplitude level;
wherein the second amplitude level is substantially zero, and
wherein substantially zero comprises a magnitude of the second amplitude level is at most a predetermined fraction in the list of 1%, 2%, 5%, and 10% of a magnitude of the first amplitude level.
18. The user device of claim 17 , further configured to:
demodulate the first message element according to a first modulation state of the modulation scheme; and
demodulate the second message element according to a second modulation state of the modulation scheme, different from the first modulation state of the modulation scheme.