Abstract: A base station and wireless device are configured to support TDD operation. In exemplary embodiments, the base station or UE can make use of the available symbols in the DwPTS or UpPTS of a special subframe respectively for NB-IoT transmissions. In one example, the base station can use OFDM symbols in the DwPTS to repeat in a predetermined manner some of the symbols transmitted in an immediately preceding downlink subframe, or in a succeeding downlink subframe. In other embodiments, the UE can use symbols in the UpPTS to repeat in a predetermined manner some of the symbols transmitted in the immediately succeeding uplink subframe, or in a preceding uplink subframe. The symbols repeated in the special subframe can be coherently combined at the receiver with corresponding symbols transmitted in a downlink or uplink subframe to improve decoding performance, reduce errors, improve channel estimation, and increase system capacity.

Abstract: A base station and wireless device are configured to support TDD operation. In exemplary embodiments, the base station or UE can make use of the available symbols in the DwPTS or UpPTS of a special subframe respectively for NB-IoT transmissions. In one example, the base station can use OFDM symbols in the DwPTS to repeat in a predetermined manner some of the symbols transmitted in an immediately preceding downlink subframe, or in a succeeding downlink subframe. In other embodiments, the UE can use symbols in the UpPTS to repeat in a predetermined manner some of the symbols transmitted in the immediately succeeding uplink subframe, or in a preceding uplink subframe. The symbols repeated in the special subframe can be coherently combined at the receiver with corresponding symbols transmitted in a downlink or uplink subframe to improve decoding performance, reduce errors, improve channel estimation, and increase system capacity.

Abstract: A pilot channel signal for time-division multiplexing with one or more traffic channel signals in a broadcast/multi-cast signal and for code-division multiplexing with a continuously transmitted pilot channel signal is described. In an exemplary method for transmitting a broadcast/multicast signal, a pilot symbol sequence is obtained for each slot of one or more frames of the broadcast/multicast signal, so that the pilot symbol sequence varies for each slot of a given frame. The pilot symbol sequence for each slot is spread with a channelization code, and the spread pilot symbol sequence for each slot is scrambled, using a scrambling code, to form a first pilot channel signal. The first pilot channel signal is transmitted so that it is time-division multiplexed with one or more traffic channel signals transmitted during each slot and code-division multiplexed with a second pilot channel signal transmitted during all slots of the one or more frames.

Abstract: The quality of a received signal in a non-linear receiver is estimated using a coupling matrix G or Q that describes the interaction of symbols in the received signal with other symbols and/or how the impairment (noise and interference) interacts in the received signal. The coupling matrix is also useful for joint detection. The signal quality estimate may include, e.g., the minimum eigenvalue, and other functions, such as the determinant and trace of the coupling matrix. When G or Q varies with each block, as in CDMA systems employing longcode scrambling, a representative matrix can be used, such as a matrix of RMS values or average magnitudes of real and imaginary components. The signal quality estimate can be expressed as a bit error rate (BER).