Fixed frequency-time division duplex in radio communications systems

A wireless communications system, comprising:

• a plurality of mobile stations;
• and
• a first base station configured to transmit downlink communications signals to said mobile stations via a first carrier frequency and to receive uplink communications signals from said mobile stations via a second carrier frequency, the downlink and uplink communications signals being transmitted and received via successive time division multiple access frames, each frame including a plurality of time slots in each of the first carrier frequency and the second carrier frequency,
• wherein, for each active communications link between said first base station and a mobile station, a first time slot in each frame is allocated for downlink communications and a second time slot in each frame is allocated for uplink communications, the first and second allocated time slots being separated in time by a fixed time offset, and
• wherein a first partition of the time slots within each frame is reserved for downlink communications from said first base station to the mobile stations and a second partition of the time slots within each frame is reserved for uplink communications from the mobile stations to said first base station, such that a first portion of the time slots within each frame are reserved for downlink communications and a second portion of the time slots within each frame are reserved for uplink communications.

A method for conducting communications between base stations and mobile stations in a wireless communications system, comprising the steps of:

• co-locating at least two base stations;
• transmitting communications signals between the co-located base stations and the mobile stations using time division multiple access frames, each frame including a plurality of time slots, wherein downlink communications signals from the co-located base stations to the mobile stations are transmitted via a first carrier frequency and uplink communications signals from the mobile stations to the co-located base stations are transmitted via a second carrier frequency;
• and
• for each of the co-located base stations, reserving first and second partitions of time slots within each frame for downlink and uplink communications, respectively, such that, at any moment in time, at most one of the co-located base stations is transmitting via the first carrier frequency and at most one of the co-located base stations is receiving via the second carrier frequency.

A wireless communications system, comprising:

• a plurality of mobile stations;
• and
• a first base station configured to transmit downlink communications signals to said mobile stations via a first carrier frequency and to receive uplink communications signals from said mobile stations via a second carrier frequency, the downlink and uplink communications signals being transmitted and received via successive time division multiple access frames, each frame including a plurality of time slots,
• wherein, for each active communications link between said first base station and a mobile station, a first time slot within each frame is allocated for downlink communications and a second time slot within each frame is allocated for uplink communications, the first and second allocated time slots being separated in time by a fixed time offset, and
• wherein a first partition of the time slots within each frame is reserved for downlink communications from said first base station to the mobile stations and a second partition of the time slots within each frame is reserved for uplink communications from the mobile stations to said first base station;
• at least one additional base station co-located with said first base station and configured to transmit downlink communications signals to said mobile stations via the first carrier frequency and to receive uplink communications signals from said mobile stations via the second carrier frequency, the downlink and uplink communications signals of each of said additional base stations being transmitted and received via successive time division multiple access frames, each frame including a plurality of time slots,
• wherein, for each active communications link between an additional base station and a mobile station, a first time slot within each frame of said additional base station is allocated for downlink communications from said additional base station and a second time slot within each frame of said additional base station is allocated for uplink communications to said additional base station, the first and second allocated time slots being separated in time by a fixed time offset,
• wherein a first partition of the time slots within each frame of each additional base station is reserved for uplink communications and a second partition of the time slots within each frame of each additional base station is reserved for downlink communications, and
• wherein the first and second partitions of the frames of each of said base stations are structured such that, for each time slot in each frame, only one of said base stations is permitted to transmit on the first carrier frequency and only one of said base stations is permitted to receive on the second carrier frequency.