Wireless telecommunications system for high-mobility applications
A wireless telecommunications system that mitigates infrasymbol interference due to Doppler-shift and multipath. Embodiments of the present invention are particularly advantageous for wireless telecommunications systems that operate in high-mobility environments, including high-speed trains and airplanes.
1. A process comprising:
receiving a data item d(1,1) and a data item d(1,2);
generating a waveform φ(1,1) and a waveform φ(1,2) wherein:
(i) the waveform φ(m,n) is partitioned into N time slots 1, . . . , p, . . . , N,
(ii) time slot p of the waveform φ(m,n) comprises a basic waveform b(m) multiplied by exp[2n(n−1)(p−1)i/N],
(iii) the waveform φ(m,n) is multiplied by the data item d(m,n),
(iv) M and N are positive integers greater than 1,
(v) m is a positive integer in the range mε{1, . . . , M}, and
(vi) n and p are positive integers in the range nε{1, . . . , N};
modulating a radio-frequency carrier signal with the sum of the waveform φ(1,1) and the waveform φ(1,2) to generate a modulated radio-frequency carrier signal; and
radiating the modulated radio-frequency carrier signal into a radio channel via an antenna.
2. The process of claim 1 wherein j and k are positive integers in the range mε{1, . . . , M}, and
wherein basic waveform b(j) and basic waveform b(k) are orthogonal for j≠k.
3. The process of claim 1 wherein the basic waveform b(m) is waveform m in an M-ary stepped-pulse waveform scheme.
4. The process of claim 1 wherein the bandwidth of the radio channel is B Hz, and the duration of the basic waveform b(m) is M/B seconds.
5. The process of claim 1 wherein the bandwidth of the radio channel is B Hz, and the duration of the waveform φ(m,n) is M·N/B seconds.
6. A process comprising:
receiving a data item d(1,1) and a data item d(2,1);
generating a waveform φ(1,1) and a waveform φ(2,1) wherein:
(i) the waveform φ(m,n) is partitioned into N time slots 1, . . . , p, . . . , N,
(ii) time slot p of the waveform φ(m,n) comprises a basic waveform b(m) multiplied by exp[2n(n−1)(p−1)i/N],
(iii) the waveform φ(m,n) is multiplied by the data item d(m,n),
(iv) M and N are positive integers greater than 1,
(v) m is a positive integer in the range mε{1, . . . , M}, and
(vi) n and p are positive integers in the range nε{1, . . . , N};
modulating a radio-frequency carrier signal with the sum of the waveform φ(1,1) and the waveform φ(1,2) to generate a modulated radio-frequency carrier signal; and
radiating the modulated radio-frequency carrier signal into a radio channel via an antenna.
7. The process of claim 6 wherein j and k are positive integers in the range mε{1, . . . , M}, and
wherein basic waveform b(j) and basic waveform b(k) are orthogonal for j≠k.
8. The process of claim 6 wherein the basic waveform b(m) is waveform m in an M-ary stepped-pulse waveform scheme.
9. The process of claim 6 wherein the bandwidth of the radio channel is B Hz, and the duration of the basic waveform b(m) is M/B seconds.
10. The process of claim 6 wherein the bandwidth of the radio channel is B Hz, and the duration of the waveform φ(m,n) is M·N/B seconds.
11. A process comprising:
receiving a data item d(1,1) and a data item d(2,2);
generating a waveform φ(1,1) and a waveform φ(2,2) wherein:
(i) the waveform φ(m,n) is partitioned into N time slots 1, . . . , p, . . . , N,
(ii) time slot p of the waveform φ(m,n) comprises a basic waveform b(m) multiplied by exp[2n(n−1)(p−1)i/N],
(iii the waveform φ(m,n) is multiplied by the data item d(m,n),
(iv) M and N are positive integers greater than 1,
(v) m is a positive integer in the range mε{1, . . . , M}, and
(vi) n and p are positive integers in the range nε{1, . . . , N};
modulating a radio-frequency carrier signal with the sum of the waveform φ(1,1) and the waveform φ(1,2) to generate a modulated radio-frequency carrier signal; and
radiating the modulated radio-frequency carrier signal into a radio channel via an antenna.
12. The process of claim 11 wherein j and k are positive integers in the range mε{1, . . . , M}, and
wherein basic waveform b(j) and basic waveform b(k) are orthogonal for j≠k.
13. The process of claim 11 wherein the basic waveform b(m) is waveform m in an M-ary stepped-pulse waveform scheme.
14. The process of claim 11 wherein the bandwidth of the radio channel is B Hz, and the duration of the basic waveform b(m) is M/B seconds.
15. The process of claim 11 wherein the bandwidth of the radio channel is B Hz, and the duration of the waveform φ(m,n) is M·N/B seconds.
16. A process comprising:
receiving M·N data items d(1,1), . . . , d(m,n), . . . d(M,N);
generating M·N waveforms φ(1,1), . . . , φ(m,n), . . . , φ(M,N), wherein
(i) the waveform φ(m,n) is partitioned into N time slots 1, . . . , p, . . . , N,
(ii) time slot p of the waveform φ(m,n) comprises a basic waveform b(m) multiplied by exp[2n(n−1)(p−1)i/N],
(iii) the waveform φ(m,n) is multiplied by the data item d(m,n),
(iv) M and N are positive integers greater than 1,
(v) m is a positive integer in the range mε{1, . . . , M}, and
(vi) n and p are positive integers in the range nε{1, . . . , N};
modulating a radio-frequency carrier signal with the sum of M·N waveforms φ(1,1), . . . , φ(m,n), . . . , φ(M,N), to generate a modulated radio-frequency carrier signal; and
transmitting the modulated radio-frequency carrier signal into a radio channel via an antenna.
17. The process of claim 16 wherein j and k are positive integers in the range mε{1, . . . , M}, and
wherein basic waveform b(j) and basic waveform b(k) are orthogonal for j≠k.
18. The process of claim 16 wherein the basic waveform b(m) is waveform m in an M-ary stepped-pulse waveform scheme.
19. The process of claim 16 wherein the bandwidth of the radio channel is B Hz, and the duration of the basic waveform b(m) is M/B seconds.
20. The process of claim 16 wherein the bandwidth of the radio channel is B Hz, and the duration of the waveform φ(m,n) is M·N/B seconds.